37_Roadmaster_C

@Auldon, I think in 37 both were used, but I am not 100% sure. Others will chime in with a better answer or @carbkingmight drop by with the answer. Very nice looking car!!

@Tonz, Your note at the end is like us in the car world talking about "Polarizing" the generator. Same end effect and result.

Because "earth ground" is the ONLY true "Ground" reference. The chassis of a vehicle has NO intentional electrical connection to earth ground, however by skewing the term "ground" to actually mean "chassis common", we now have what people mean when they say "ground". It is just a matter of words. As long as the people in the conversation are on the same page it matters not. I come from a electric power systems industry and a broadcast and communications industry background. In these two careers, the term "Ground", ment very very different things and I can carry on a discussion equally well in both areas, however, if both fields come up at the same time, it is mandatory to define power system and antenna "ground" as meaning "earth ground" and electronic equipment systems "ground" as meaning "common connection" point. Now to really confuse things, both grounds CAN be the same electrical potential and the same conduction path. Clear as mud made from the ground, right 😇????

This is a 100% true statement! The term ground has been grossly skewed, at least in the US. The proper term, as used in Europe, would be EARTH. A TRUE GROUND or EARTH connection is a safety connection ONLY!!! It is what keeps you from being zapped when you touch the case of something which has an internal failure that makes the case have voltage on it. A true ground, by definition is a "Non current carrying conductor" by National Electric Code rules. In the US, we have skewed the term in some industries to equate to "Common Connection" like the chassis of an automobile. Hence the quote above. I am almost 100% sure that what was happening is that when the battery was disconnected, "When the car was running", the generator picked up the load and in some way with the correct polarity. The actual question is why was there no smoke from the wiring or the battery ay the generator "Battery" cable would have had a lot of current flowing through it. Ah for the luck of children and fools..................

My approach is to assume ( Yep, there is that word again) that the crank pulley is right and go from there. This is by no means a fast and true rule. Anything could be in the wrong place, but without knowing, you have to start somewhere.

Hi Jim, I am glad you were able to give some rides and enjoy the car. I do not know the gearing of a 40mSpecial, but if it is like the earlier years freeway speeds will be really pushing things. Others will chime in who have first hand experience. Many people with the Special are begging for an easy way to change the rear end gears for freeway speed. Unfortunately, there is no EASY way to do this.

I am retired out of the electrical and electronics field. I am NOT an engineer nor do I have any engineering specific education. In my practical experience, there is no reason, I know of, that would make any difference. From a voltage, current or power standpoint both are the same. The only reason it might, I stress Might, make any difference is if the product had to work in conjunction with other pieces of equipment. in a combined system. A vehicle is a stand alone assembly so there is no need to match anything. With that said, I think it was simply at the whim of the engineer designing the electrical system for the vehicle. A lot of people think electrical current (electrons) flow from positive to negative. but as @m-mmansaid, current actually flows from negative to positive so who knows??????????

@clipperfan, The wire you replaced in the distributor is a bit special and needs to be replaced with proper wire for long term best results. The breaker plate in the distributor moves with the vacuum advance and continuously flexes that wire and if not proper it will break. Check other forum posts for more details and where to get one.

@clipperfan, you will need to chase down the wiring to that Ford solenoid to confirm its operation. There is NO reason that would be needed to bypass the throttle start operation. It may be that the previous owner added it because they did not understand how the autostart worked. It can be done with an extra relay/solenoid, but it just adds more confusion and failure points. My 37 Roadmaster has a pushbutton start switch and there is nothing added to make it work, just a little modification to the wiring. When I get done with the restoration she will have the autostart back working. Nothing makes people wonder when the car starts while both of your hands are on the wheel 🤣.

Just for general information... All Buicks from I think 1936 through 1960 had the throttle start. Maybe someone can confirm the 1936 start year.

This is a bit of a hijack, but I needed to say it here......... @edinmass, I understand and agree 100% with what you say, with a small exception. Most people starting in this hobby are not professional mechanics (especially for old iron). nor do they have the test equipment needed to do the tests you mention. Also, most do not have the cash reserves that would be needed to have these things done by a professional. In a perfect world, everything you said would be done in a specific order with the equipment required to do it properly. I do not promote the "shotgun" approach to automotive repair, be it modern or antique vehicles, but some things are fairly standard issues and the price of the parts is fairly low. If the labor is the owner and/or friends doing the work it is really an acceptable option...In my opinion. I am not really critical of what you said, but I still feel the OP was not running wild in the parts store 😇. As for electric fuel pumps and just stuffing in a carb kit to solve fuel problems, I am 100% in agreement with you. BAD BAD BAD idea!!!!! I also agree about electrical grounds. Every connection point MUST be clean and tight. Extra ground straps are also a must as old cars ALL have rust and/or other poor electrical conductivity issues throughout the mechanical joints in the body, frame and so on. Paint on a new restoration is even worse. Yes, grounds are a bugger and then some!! I really like your idea about creating an orderly list of the approach to troubleshooting various systems. I am best with electrical as I am retired out of the electronics and high power broadcast industries. I think many members and especially people new to the hobby would benefit from this as it creates order from chaos. I also want to thank YOU for everything you do to help people keep this hobby alive!!! We are loosing knowledgeable people faster than we can teach new ones. Have a shot for me and PLEASE keep passing along what you know!!

@Rock10, The accelerator pump cavity is part of the carb casting. Are you asking if the pump plunger is available as a separate part or ??? Normally the plunger is not a separate part. If you need one either buy the carb kit with one or you are going to have to call and ask. Jon, Carbking, may be able to help you.

@edinmass, I think the OP IS diagnosing the problems with the suggestions from the members. He has confirmed small battery cable problems and is replacing with large cables. He did diagnose carb accelerator pump failure and is rebuilding the carb to repair that problem. The only thing not addressed is the grounding of the starter directly. The OP said the battery grounded to the frame. Others here said there should be a ground cable from frame to motor or the battery ground should be attached to the motor and then a ground cable from motor to frame. In any case, diagnosis IS being done and failures addressed properly. Is this not how people learn about new subjects? Hmmmmm......

Hopefully a PA person will chime in... @edinmass, Help????

Neil has said it all. Both Rhode Island Wire and YNZ Yesterdays Parts have the individual wire and wiring harnesses available. I got a new harness for my 37 Roadmaster from YNZ and had some mods included (larger gauge for modern headlights, extra wires for electric fuel pump and driving lights and mods for turn signals and the switch). I was very happy for the price. Another thing to think about is the outer harness covering. It is very hard to do that on your own. When these companies make harnesses they weave the outer cover to properly fit and allow the wires to exit the harness where they should. My vote is to buy the harness from a reputable company. Just my thoughts...

Hi Paul, I think there may be more going on because of your description of the problem. the first thing to test is the actual gauge in the dash. An easy test with the tank out is to check the gauge with the ignition "On" and the tank sender wire disconnected. The gauge should read over full. Next ground the tank sender wire. The gauge should read below empty. If these checks are Ok, the sender is next. The float arm should move up and down easily and smoothly. If it does, I would hook up the sender to the cars tank wire and securely ground the sender frame to the chassis. With this hookup, turn on the ignition and slowly move the float arm up and down while watching or having some watching the gauge. If the gauge goes up and down smoothly, I would order a set of floats from Bobs and reinstall everything. That is my basic approach. If you do replace the sender, you will need to adjust the float arm by bending to match your tank. Easy to do, but it takes a little time to get it right. Others will chime in on this...

I can't help with your question, but where are you located? If in the Pacific Northwest I might be interested in your original drivetrain parts.

@Oldtechhas it right at this point. The OP has confirmed that one set of points is not opening. At this time there is no need for compression testing. Get the ignition working THEN if there are still issues move on to further troubleshooting.

Absolutely as @Bloo said above. Ask @edinmassfor recommendations. There is NO reason cold stitching can not be done on curved surfaces. It just takes more care and time. I would only put a torch to that block as an absolute last resort.

If the mods do not like the funny I posted they can remove the WHOLE post!!! Get a life

I will freely admit to preferring stock to modified, unless it involves safety, 100% of the time. With this said, I would get the stock fuel system working first, then evaluate the need for adding another failure point to the car. Electric fuel pumps have their place, but like 12 volt conversions, they are not a fix all!!!! Ok, rant off 😇.

Another temporary fix would be to use a piece of "Solderwick" or equivalent as the wire. If you do go this way, crimp the terminals on the wick with the insulator removed and a little extra wick going through the crimp. Next, VERY carefully add a LITTLE solder to the exposed end of the wick. Make sure the connection is heated before the solder is added. Expect to goof a few times unless you are an experienced solderer. As the name implies, Solderwick is designed to absorb solder for desoldering parts from circuit boards. You MUST ensure that the solder does NOT get into the flexing part of the wick. If it does the wick will not be flexible any more and that defeats the purpose of using the wick. I have this stuff on hand. If I did not, I would just order the wire from Bobs and wait for the delivery. Fix it once and fix it right 😊.

Great work! That is how you can make an expensive tool out of cheap parts... relatively speaking.

To expand on this a little... Current is the flow of electrons through the wire. Like water is to the pipe mentioned above. In measurement terms: Volts=pressure, current=gallons per minute, resistance=losses (friction, obstruction, height etc), watts does not have a common equil, but it is the actual "power" created by the voltage and current. In water terms watts is kind of like the saturation from a sprinkler. The more pressure and/or gallons per minute the faster the lawn gets watered (the work expected). Kind of a clunky explanation, but it might help nonelectrical minded members 🙂.

Fuses are an absolute MUST for simple safety. A disconnect switch can be a blessing or a curse as mentioned above. If you drive the car fairly often a honestly good switch is fine. Cole Hersee makes commercial grade battery switches. Grab your pocket book, they are expensive, but what is your car/home worth? These are the switches normally used on fire trucks and other critical use vehicles. Now if a disconnect is only wanted for storage or occasional use, a good wrench, to disconnect the battery cable, is 100% reliable and cost effective.