Doctor's Pontiac

Thank you for the very clear photos, I appreciate it. Seems the design of mine is about the same. The back of the vent is always hidden from access given that the vent opens up to the front and is pivoting on the back. I see in your photos that there are 2 hinges, one on each side in the back of the body of the vent that can only be reached from under the dash/cowl. I wanted to explore as much as possible how this is built so I attempted to disassemble as much of the vent as possible to study the case and I show my findings below.

Made no progress. It is impossible to see the cowl from below dash because is covered by big heater box. There must be a way to access from the top once the screen is removed. That is where I am stuck. These are the instructions from the Fisher manual and schematic of parts book: HOW CAN I DO STEP # 2 ? Bolts are hidden. Thank you

The battery ground cable should be cleaned and connected tightly on both ends but your issue is localized to parking lights and turn signals. Those are the sites where poor ground may be causing the problem and not a systemic fault attributable to the battery ground. After cleaning and reconnecting the battery ground cable, remove the bulbs and check if you get volts at the socket and if you do then add a jumper wire with a simple alligator clamp from the socket to a good ground on the body or frame and test if lights work. If they do, it means poor ground connection at the socket. I did that way and helped to fix tail lights.

The 41 Oldsmobile has the ground cable from the battery to the front of the starter motor where there is a large bolt to attach the ring from the cable. Here is the wiring diagram to confirm it. Yours is a 48 model and may be different. You need to find a wiring diagram to make sure. Shop Manuals typically have one. In reference to the gauge/size of battery cables, you may find helpful to read my recent post in this forum regarding problems to start my car which was resolved with help of several knowledgeable Forum members by getting the correct cable gauge, a 00 (also called 2/0). The post name is "Ignition switch wiring connection of 41 Oldsmobile".

It happened constantly on concrete paved road, the type found on Interstate freeways, with numerous parallel grooves on the surface that seem to pull the wheels all the time to one side or the other and created a very wobbly and unstable control of the car at a speed above 45 MPH. The problem happened only with the old bias ply tires and is totally gone now with the new bias looking radials. I am having an alignment this week and will also check the toe in/out adjustment as you suggest. I wanted the original poster to have this information considering that we have nearly same cars.

I need help to remove the cowl vent lid of my 41 Olds sedan to clean it and check what may be causing some loose play on one side. No specifics in the shop manual and found only minimal information on a Fisher body manual regarding procedure to remove it. The only clear instruction is to first disconnect the linkage under the dash. There are other hinges that are not accessible from below the dash because there is a big box there for the heater and not from above because there is a screen in front, and I can not remove the screen either. I can not imagine the large heater box has to come out for this job. These photos show what I have. I hope to get some suggestions what steps to follow. View from the L side, can see 2 screws, one in the center and one on the extreme L side attached to the screen. I removed them and no way the screen will come out as there is no clearance on the front part despite the lid already reaching its highest possible position plus this "rivet" shown in photo. From the R side, the screw is missing on the end and again I see this smooth round head that don't know what it is but seems also holding the screen in place. I looked carefully at the screen and there is a lot of stuff INSIDE the screen. Debris and bugs are supposed to be stopped OUTSIDE. Is this a filter element or is what seems an abandoned nest? The interior was in very good condition when I bought the car with no traces of pest having nested inside. There is no odor. It seems to stop any flow of air inside so I presume this is a previous unwanted guest. The dried up cracked gasket visible. The linkage that connects the cowl with the handle under the dash is easily visible and ease to disconnect with a small bolt with a nut shown in photo. Presumably, this will permit the cowl lid to be pulled upwards once the other hinge bolts are removed. That is what the instructions state without telling how to remove them!I I hope to have input so I can continue the repairs. Thank you very much, Manuel

I’ve just installed today 4 new bias- looking radials from Coker on my 41 Oldsmobile 78 sedan. The sidewall script states “ maximum 41 lbs “. Bias ply tires recommended pressure in the shop manual is 26-28. I chose 34 lbs knowing has to be much more than bias but not too high that will ride too stiff. In a test drive feels fine and will leave there until someone who knows better advises to change. You may be interested in checking my post about the mounting of the tires earlier today.

After months of delay blamed on Covid and supply chain problems, I received my Coker tires, bias-ply-like radials, 16.5 x 16, same size as factory and also with a set of recommended inner tubes. Today I went to a tire shop and spent some time observing the manager as he removed my 4 old bias ply tires and mounted the new radial ones. He was kind enough to let me take pictures of the process for the "apples-to-apples comparison" Bloo refers to. It is a busy shop so I had to shoot pictures when I had a chance but no time to stop him and delay his work for careful measurements to report here, which would be ideal. My observations: 1. The Coker tires are actually a bit narrower than the old bias ply tires, just the opposite of what was commented here before. There was no difference at all in effort to turn the steering wheel 2. The Coker tires look taller. I did a crude quick measurement and is almost 1 inch total. However, they arrived much flattened and perhaps will become wider and shorter after placed on the car. The beads from both sides were literally touching each other after removing the wrap placed for shipment and required a lot of force to separate them to apply some powder before mounting on the wheel. Radial on the L and old bias ply tire on the right. Both are mounted on the rim already for this photo Radial on the L and bias ply tire on the R. The slight height difference is observable 3. Next photo shows the Radial already installed on the passenger side while the bias ply still on the driver side. Hard to see because of the light in the background but both, the tech and myself, could clearly see that the radial was a bit taller and closer to the floor 4. We dropped the car to the floor to check clearances and there was plenty of space between tire and fender and proceeded to mount the other 3 tires. 5. Coker sells these tires as same size of the originals. The next 2 photos show the size as written on the sidewalls. is Is the height difference important? I drove home and decided to test on the Interstate, at 60 mph there was a dramatic improvement compared with my old tires, that appeared as an undecided voter, one moment pulled to the L and next moment pulled to the right and felt so unsafe to the point that I drove no faster than 45 MPH. May be the old tires would be better if they had been balanced. We saw no weights on the rim for balancing them. These are the first bias looking radials I have and they look close to stock but drive much better so I am happy with this decision. Manuel

Thank you for your comments. When I bought the car I remember seeing the Motorola radio sitting on the floor at his barn. Previous owner intended to install it and actually had receipts of having the radio repaired (back in late 80s). I had the radio refurbished by Joe Cilluffo from joesclassiccarradios.com and he did a perfect job in function and cosmetics. The radio controls color matches the instrument cluster, glovebox door and transmission lever.

Like most cars back in 1941 my Oldsmobile came without a radio. It was a dealership available option and the installation procedure is described in the shop manual. Although I prefer everything as stock as possible, adding an original radio does not seem to alter much the stock qualification of this car. I have to have a radio because most of my driving I do alone and I like the company of music or news coming from the vintage AM box. Since my car had no radio from factory it did not have a body hole for an antenna. For months I looked for any factory service template or service bulletin to know exactly where to drill the hole with no success. These are the steps I followed until I could complete the job yesterday. 1. Had to rely on original car photos found online to have a reference of location of the hole on the cowl, like the one below, which was very helpful 2. I found an old NOSR antenna on e bay about a year ago which is "period OK" until I can find an original stock antenna that might exist somewhere in the universe and which will be easy to replace. https://www.ebay.com/itm/234602111641 3. I estimated center of hole will be 1" behind the edge of the cowl and 3" from the L side. Just my guess based on photos and comparing with my car cowl 4. I gently punched a tiny dent on the cowl where the center of hole will be and used masking tape to cover a 2" x 2" area around the drilling area to protect the paint (sorry no photo) 5. Started drilling a pilot hole with a very thin bit and increased the size progressively until hole was 1/4". 6. The body steel is strong, don't know the gauge but seems about 1/16" thickness. I have never cut a hole in a car and was nervous to mess up, so I first practiced several times in a piece of scrap metal plate until I felt a bit more confident. First tried using a step drill but did a terrible job. Then used the hole saw and you can see got better results 7. Then I took a deep breath and used a new Milwaukee 3/4" Hole Dozer hole saw with a pilot drill bit in the center and started drilling at very low RPM 250, adding periodically some WD-40 as a lubricant. After a few minutes the hole was cut clean. Big thigh of relief ! The antenna came with instructions to cut a hole of 13/16 diameter but when I practiced drilling I noticed that a 3/4 hole is exactly the size that is needed. Distance from center of hole to cowl edge turned 1-1/8 inches Distance from center of hole to L side of body turned to be 3-1/8 inches Viewed from below the dash. The headlight switch bar removed to have better access to work under the dash 8. Removed all the masking tape and used a round file to smooth the edge of the hole 9. With a small brush applied some primer and then touch-up paint to the recently cut wall to protect from rust 10. Installed antenna mast from below the dash with the components arranged in the following order: The tooth washer sits directly under the cam-shaped base which -thanks to this shape- permits adjusting the direction of the antenna. These 2 pieces, washer and base, are the only ones that go under the cowl. All others must be installed from the top and the nut is used to secure all components once a correct vertical position is achieved. 11. Before tightening the nut, applied some clear silicone around hole under the large rubber gasket to help prevent any water leak Installed antenna My only regret is that there is still room to drill the hole more to the L to diminish any visual interference when driving. I did not appreciate that option in the middle of the battle but honestly, when I sat on the driver seat and moved the car around the block to test the radio, I was totally comfortable with the visuals and it looks in about the same location than the initial original photo. Antenna has excellent ground and reception is loud and clear and as good as AM can be in an 80 year old radio Manuel

That is exactly the way I have been doing and feeling with my Olds, except the cigar. In almost 2 years I have worked countless hours, spent about $ 3K in parts and supplies and experienced the immense satisfaction - at an age of becoming a senior - of learning how to fix car components that I always perceived were mysterious. I enjoyed the accomplishment of the electrical dash repair more than the others because my weakest skill is fixing anything electrical!

I will describe what I enjoyed the most of all the jobs I have done on my Oldsmobile.I retrieved my 41 Oldsmobile Series 78 sedan in Feb 2021 after 30+ years of enclosed storage and have now completed a general restoration and began driving the car. As usual, had many days of frustration and many of happiness as the job progressed. However, what gave me the most joy was the experience I had last night when I finally took her for the first drive at night to test a lot of electrical fixes I have been working on. There were many wires that needed attention under the dash and since my goal is always to have everything that belongs to the car in working condition, I spent quite a lot of time making sure every single light and electrical component on the dash worked as original. Initially, only the ammeter gauge was in working condition. I restored the cluster and all other electrical components. After testing all lights in my garage, I was anxious to see how all the lights will work when car is out during the night. Yesterday was the day and after I finished installing clock and radio and fixing a starter problem that delayed the process for more than a week, went out for a drive at sunset. A very cool dry night with mild breeze in Western SD was perfect and I drove about 30 miles ecstatic looking at the dashboard the whole time!!! (well, not really, had to keep an eye on the road also). The dimmed 6 volt lights are so nostalgic, and contrary to what I expected they provide just enough light to see the instruments once is dark outside. The clock for instance, is 2 candle power bulb!! Imaging reading a book with just 2 candles at your side I stopped for this photo when I entered my street from the highway. I was surprised to see a light on the heater switch (below on the left) that I did not even know was there. The entire dash is very harmonious with some lights on the instruments, some on the middle on the radio and the glovebox clock on the right. Not seen is the glovebox light that turns on when opening the glovebox, thanks to a mercury tilt switch installed on the hinge. Even the small green light on the transmission selector is visible. That is "cool" as the younger ones say. Just another view Of course testing the radio was a major part of the ride. Here is the antenna on the front seat, still not installed. I held the antenna out the window to provide ground with my hand and this 80 year box played perfect country music until my arm started aching so had to turn the radio off. I will install the antenna on the cowl confident that the radio works. I also installed a capacitor to the coil cable on the ignition switch and may be is doing the job as there was no noise interference. Finally, when I got to my shop to park the car, I opened the garage door and turned facing the car. I was surprised to see how close the headlights are to each other. When is dark and you only see the headlights and do not see the car approaching, they look so close to each other that appears to be a very small vehicle. I said, what is that? a Crosley? May be other Forum members can post their most joyful moments working on restoring their vintage cars.Manuel

Very nice original car that appears can be on the road with not too much work. Has the true patina. With cleaning and polishing the paint will likely look terrific but the spots with surface rust on the rear are beyond the reach of a polish. I posted several times the work I did on my 41 Oldsmobile series 78 that you may want to read. Our cars have many things in common, although significant changes came in 41 with the Hydramatic transmission. I read your post about tires recently. Mine was stored in late 80s and I still have the bias tires from then on the car and had driven around for a bit over a year while working on several restoration jobs since I got the car in Feb 2021. It is incredible how after 30+ years they look fine and hold air. It is dangerous though because rubber dries up so I finally could buy a new set of Coker bias-look radials that will be installed next week. They look the same as the bias, need tubes and are very expensive. Good luck bringing the car back to life soon! Will enjoy seeing the progress you make. Manuel

Finally could resolve starter problem successfully !! Found a 2/0 (00) cable at Fleet Farm store. Before installing it I hooked a spare 12 volts battery directly to starter and it worked perfectly and confirmed the starter motor is fine. Then I installed the new positive cable and the motor started spinning happily. It is a 24 inch long cable and a few inches longer than correct but I don’t mind if it does the job well. It is good quality copper. In conclusion, careful cleaning of ALL contacts plus new cable resolved the “dead starter” problem. Thank you all for your replies and suggestions. You made the job a lot easier! Manuel

I am following all suggestions that I receive and appreciate everyone's comments that help a lot to learn electrical trouble shooting. Unfortunately, I still can not identify what the problem is with my starter motor. What initially I thought was a wrong wiring at the ignition turned to be a problem with either the battery, the battery cables or the starter motor. I learned that lesson from your posts so I keep focusing on sorting out which one of the 3 components failed suddenly. Over last 3 days (nights actually, as I work during the day and then spend time in the garage late at night) I did the following: 1. Went back to the basics. Removed both positive and negative cables and cleaned them shiny and free of any debris 2. Did the same with both battery posts and all the copper connectors in the starter switch 3. Then left the battery on charger overnight 4. I connected everything again last night (must be the 15th time at least I have done it), crossed fingers and tried to crank the starter. This car has a mechanical fuel pump and typically takes 3 attempts until has enough gas in the combustion chamber to fire. I had a moment of euphoria because as soon as I hit the pedal it cranked strongly as used to be the case. I waited few seconds and pushed the pedal a 2nd time and it cranked again pretty good and the engine made the usual attempt to fire. I knew that the next time it should fire so hit the pedal a third time and............total silence, nothing, nada. 5. Again left battery in charger, just in case the battery is failing and today attempted to crank but had same outcome, no cranking. 6. I also hooked with the voltmeter to both battery posts while engaging the starter and volts dropped minimally from 6.32 to 6.26 (without the starter motor cranking). This test presumably means battery is OK 7. I noticed that the button on the starter switch located on top of the starter motor has a long path until it reaches the copper contact inside. I thought that perhaps it is not reaching the contact sufficiently and decided to fabricate a small "hat" of a copper sheet and placed it on top of the contact that is on starter (see photos below). Now when the button is pressed it travels about 1/16th of an inch only and it hits the contact on the starter, but again, no cranking. 8. Tomorrow I will use a spare 12 volt battery and connect directly to the contact on the starter. 12 volts will not damage the starter if used for a few seconds plus I will have it disconnected from the car electrical system so lights will not be burned. If the starter does not spin with 12 volts using jumper cables I will come to the conclusion that is a starter problem and will remove it. 9. I will buy a positive cable tomorrow from Tractor Supply and will try. Prefer to spend 30 dollars that may save the work of removing and repairing the starter motor. A new cable will give me assurance that the problem is or is not a faulty positive cable Please don't get tired of my post! I am very persistent and will figure out and comments are very helpful to provide ideas.😃 Manuel

I did test directly to the battery and have 6.26 volts. All lights and radio work fine and battery is frequently on a trickle charger and fully charged. Positive cable connects to top of starter motor to the switch as shown in initial photos. Negative ground cable connects to a large bolt in the front of starter as well. Both connections clean and tight. Positive cable looks intact, has been in the car for 35 years but car was in storage until 2 years ago, so may be corroded inside? Should I try getting a new cable or is the starter that failed? I don’t understand how to interpret the voltage drop to zero when engaging starter. Can you explain?

I followed Bloo's suggestions and hooked the multimeter with the negative to the starter case and the positive to the connector where the battery cable is attached and I got 6.26 volts. Then asked my daughter to hit the starter button for several seconds and the voltage immediately drops to near zero when starter engaged. I did it also with my test light and the light turned off instantly when the starter gets engaged (but no cranking at all, starter is totally silent). I repeated several times to make sure reading is accurate and got always same result. I removed and examined the positive battery cable which looks fine externally. Can you interpret these findings for me? Is the marked voltage drop indicating that the starter motor is trying to pull current but is not getting any? I will look for a new battery cable to test again during the week if that may be the problem. I am hopeful that I won't have to remove the starter. That is a very difficult job for me, working alone with all sort of aches and poor physical abilities. EmTee. I thought of doing that also but the large copper piece is riveted to the starter button (visible in my initial photo) and contained in a square shape seat and therefore can not be flipped. I don't want to remove the rivet to flip the contact because don't think I will be able to repair the damage.

This is what I did based on suggestions and sadly it seems that the starter motor is dead: 1. Tested the power to coil with ignition ON and got voltage on the positive wire of the coil. With ignition OFF there is no voltage at the coil 2. Removed the starter switch located on top of the starter. It is a very simple connector between the battery and the starter and it looks fine to me although has a small wearing on one side of the copper connector (see photo below) 3. The connector on top of the starter looks fair with minimal wearing in my view (photo below). I cleaned it with a steel brush and then did a direct connection between the positive cable of the battery and the starter holding the battery cable tight to the connector on top of the starter by hand. Based on Oldtech description it can only be 3 things: cable, pedal switch or the starter itself. I think I by-passed the switch with this test and I have nothing in response, just a few sparks at the negative battery terminal and not a hint of starter motor spinning Is this sufficient evidence that the starter motor is the problem?

Before going to the starter I need to confirm how the wires connect at the switch. How do I test if wires at connectors # 1 and #3 are correct? Any suggestions?

It is, and worked perfectly every single time since I got the car. I also activated the starter by hand from under the hood emulating what the pedal does and nothing happened

The starter on my 41 Oldsmobile is suddenly dead. 6 volt original. It was working perfectly until about a month. Since then I have not attempted to start the engine as I was concentrated on installing the restored radio and the glovebox with a clock and all its wiring for lights as well. The radio requires a power wire to the ignition switch. Yesterday I finally finished the job and today wanted to go out for a ride and test how radio and instrument lights work. When I turned the ignition key and pressed the starter pedal there was absolutely nothing, not a click, not a hum, nothing at all. Many attempts and no signs of power to the starter. I am very suspicious that I placed the wires of the ignition in the wrong connectors when adding the radio wire and need help to sort it out. The switch has 3 connectors shown on this photo from today, labeled 1-3, taking from above and behind the dashboard (I can not see what is in the photo, the camera is the only thing that fits there). Driver's side is the R on the photo. I added the radio wire to connector # 1 plus a capacitor also on same connector. Connector # 2 has a wire coming from an aftermarket turn signal flasher which works well. The pack of red wires going to connectors # 1 and # 3 may have been accidentally swapped and placed in the wrong side. It is extremely difficult to reach this area. There is no direct vision and with so many wires getting together it is very challenging to tighten the screw that holds them to the connector. Would like some opinions before messing up more with this wiring. In case is helpful: - Battery is fully charged and worked great until now - All lights work well (they have their separate circuit not connected to ignition) - Radio works - With a test light, I have voltage on connector # 1 all the time and when ignition key is turned on, there is voltage on all 3 connectors - Starter motor has voltage from the battery and ground is good. Don't know how to test the wire that activates the starter from the ignition switch (this may be the key to the problem) - Wires appear as shown in the wiring diagram but not sure how to test where each wire goes I am pretty sure is a simple bad connection and my own fault for not taking a picture before adding the radio wire. Hope is not a problem with the starter (fingers crossed). Any tips? Thank you all Manuel

Hope somebody can provide clues to further explore a taillight wiring issues in my 41 Oldsmobile. Car is stock except that prior owner added a NAPA turn signals to the steering column with 6 wires on it. This NAPA unit is f rom the 1980s and has a 3 prong flasher. He rewired car and wire colors are all over the place and useless as reference. The problem is that taillights only work when the headlights are on. I have an original headlight switch, with 2 clicks when the knob is pulled: Pulling the knob one click should turn on the front parking lights and taillights. Pulling to a second click connects the headlamps while the taillights continue on. With the modification done in my car, the click # 1 energizes nothing (actually no wire is connected to the corresponding tab on the headlight switch) . The front parking lights have only 1 wire which is used for turn signal) and therefore no parking lights or taillights are active. With 2nd click headlights turn on and tailights do the same. All 4 turn signals and flasher work fine. Taillights have 2 wires, one for stop light (white) and one for taillights (yellow), for whatever is worth mentioning. I spent hours testing taillight wires circuit with multimeter and noticed the following: 1. Two wires from taillights merge at the rear of car and extend through the roof of the car to under the dash where connected to the turn signal additional harness that goes to the steering column. 2. From here, wire(s) go to the headlight switch (headlight wires come from front of car directly to the headlight switch). 3. I disconnected the taillight wire coming from back of car where it connects with the turn signal harness and plugged the taillight wire directly to the corresponding tab on the headlight switch (click # 1) and now taillights work with first pull of the knob but when knob pulled again to # 2, the tailights turn off (expected because tab for click# 1 has no continuity with tab for click #2 4. Then I spliced the tail light wire coming from back of car and divided in 2 wires, one going directly to the tab # 1 on the switch and the other to the turn signal as before. When doing this way, with the first click of the knob the tail lights turn on but also the headlights do the same!! Headlights have a totally different larger wire attached to a different tab on the headlight switch. Both, headlight and taillight wires are connected somewhere 6. Foot dimmer works well to alternate high and low beams 5. The schematics of aftermarket turn signals I find online shows no connections at all to the headlights. 6. Stop light works well Don't think the headlight switch is the problem. I got a 2nd NOS switch installed and have same problem. Is the turn signal at fault? What would you do next? I will welcome any comments how to check this further, thank you Manuel

The 41 Olds part manual does not have any group with that number. I also checked the trunk section in case a light switch is shown and again nothing to indicate there is a light. I suspect the part is somewhere in the manual but so far can’t find. I purchased a tilt switch (mercury)from eBay that has same size of the one that was in my glovebox. It is a “ new” switch, likely made years ago https://www.ebay.com/itm/293571742040?epid=1426708197&hash=item445a3d4958:g:QQoAAOSw-r5es0p8&amdata=enc%3AAQAHAAAAoE7%2B0nWsGxLBAE%2Bj5F0VV976%2FS8daVlPfMMJZDAtGvGpAIZvn6TRnGO%2ByHf2WdvETXhTrI34Yy%2BJ1bFH2zsBA3HZnv2HP1StrJQmRAPcLRHZWH30Kdum3MokB99im5D6tN%2FMWvAnRAQS6XpjnxjehWbWFZttq2tzwRQR9JnJD4jNS%2BSb8DXnw81OwvMITCtYfn7pnXEpLUKMf20CqlbZfkY%3D|tkp%3ABk9SR4zQupznYA

I have seen the glass version a few months ago and looks nice but I want to keep stock. Installing the glass involves additional skills that I lack and risk of braking it. I will look for an original in better shape than mine. A custom reproduction as offered is likely to be perfect but cost is too high and unfortunately will have to pass for now. Manuel

Since last November I have worked in restoring the interior, especially the wood graining, locks, window mechanisms , steering wheel and all new rubber of the windshield and vent windows. The dash involved a lot of electrical issues as well and I have recently posted about them. Received a lot of helpful input and now want to share the good outcome of this project. Completed the electrical dash connections and installed steering wheel and drove the boat for 25 minutes with no issues. Before and after photos of the dash. All done in my garage at the speed of a turtle. Glovebox to be installed when I receive a tilt switch for the light. Car is very dusty after nearly a year but performed well in a 20 mile drive. Upon return, I had to remove and reinstall the steering wheel that was not centered correctly but otherwise everything worked OK Will try driving in 2 weeks - Dakota weather permitting - when I will get some time off again. Thank you all for all the helpful comments. Manuel