philipj Posted October 24, 2018 Share Posted October 24, 2018 (edited) Hello all, After draining my battery down a few times due to leaving the dash light on, @$#!! I decided to check the rate of charge at idle which was about 6.35 to 6.45 volts and wonder if the voltage regulator is set up properly... By increasing the rpm I get virtually no change, maybe 6.50 volts. Is that a normal rate of charge? Edited October 24, 2018 by philipj (see edit history) Link to comment Share on other sites More sharing options...
TerryB Posted October 25, 2018 Share Posted October 25, 2018 (edited) Doesn’t sound high enough....and you posted in the parts for sale! Might want to move it. Edited October 25, 2018 by TerryB (see edit history) Link to comment Share on other sites More sharing options...
billorn Posted October 25, 2018 Share Posted October 25, 2018 How many amps are you getting? Your battery will have a resting voltage of about 6-6.5 volts and should see more than 7 volts when charging. Your ammeter should show a positive charge at anything above idel (it might show discharge at idel which is OK). As long as it shows a positive charge when your driving you should be OK. If the battery is low you should see a heavy load and then gradually lowering towards 0 as it tops off the battery. Your voltage seems a little low but I dont know if you can adjust that with the regulator which I thought was just for amperage current. The battery is the "voltage" regulator on the system so maybe it is tired? What is the voltage of the battery with everything off and disconnected? 2 Link to comment Share on other sites More sharing options...
TerryB Posted October 25, 2018 Share Posted October 25, 2018 Yes, key question there of battery voltage with engine off. A good battery should be around 6.3V. After starting and the engine above idle speed the amp gage should show charging until the battery is back to normal level. If you have an old lead acid battery be sure to check the water level as continuous charging can cook off some of the water. Link to comment Share on other sites More sharing options...
philipj Posted October 25, 2018 Author Share Posted October 25, 2018 I might need some help to move this topic to the proper location... The ammeter does show a charge above idle. I will check the resting voltage tomorrow. I wonder if I damaged the battery by leaving the instrument light on at least 3 times and running the battery to the ground... Link to comment Share on other sites More sharing options...
MCHinson Posted October 25, 2018 Share Posted October 25, 2018 If the ammeter is showing that it is charging and the engine starts normally without having to jump start it, I would not be too concerned. If you run a battery totally down to zero volts a few times, it is usually time to replace the battery. 1 Link to comment Share on other sites More sharing options...
DonMicheletti Posted October 25, 2018 Share Posted October 25, 2018 That dash light thing is just plain crazy. (did the same thing a couple of times) I rewired my '38's through the headlight switch so that the darned things can be left on. Link to comment Share on other sites More sharing options...
jeff Posted October 25, 2018 Share Posted October 25, 2018 I agree with the 6.3 volts for a fully charged battery, engine off. (theoretical 2.1 volts per cell, I believe) But, remember, this does not indicate state of charge, which is more of a capacity thing. Make sure the battery is fully charged before analyzing the voltage that the regulator is providing. It could be that the battery is "sinking" a lot of current due to low charge, and 6.5V is the best your generator can provide at that current level. Later, with a full charge, you may see a bit more voltage. I also agree that with everything set correctly, you should have something around 6.8V to 7.2V (I think this is defined in the shop manual). This is adjustable by tweaking the attachment point of the regulator spring... but it's a pretty delicate operation. Jeff 1 Link to comment Share on other sites More sharing options...
Lawrence Helfand Posted October 25, 2018 Share Posted October 25, 2018 You indicate the rate of charge not going up much with RPM and that is plainly indicating your not charging nearly enough. Should be about 8 volts or so as you need a lot more then battery voltage for charging. A 12 volt system is normal at about 14 volts so you always need at least a couple more which is why you have a voltage regulator. Link to comment Share on other sites More sharing options...
philipj Posted October 25, 2018 Author Share Posted October 25, 2018 Thank you for all your replies... A lot of good information here. My battery shows 6.11 volts resting, after driving the car for about 45 minutes yesterday, so it may be on its way out... Still, sounds like there may be a problem with the voltage regulator not charging sufficiently... 1 Link to comment Share on other sites More sharing options...
Grimy Posted October 25, 2018 Share Posted October 25, 2018 Have you put a load tester on the battery? Link to comment Share on other sites More sharing options...
DonMicheletti Posted October 25, 2018 Share Posted October 25, 2018 First check the wiring and grounds. I had a regulator problem that was finally traced to the regulator ground being bad (rust) Link to comment Share on other sites More sharing options...
philipj Posted October 25, 2018 Author Share Posted October 25, 2018 (edited) I had checked all the grounds recently while trying to solve another problem (intermittent miss that ended up being the original distributor set up with the three ball bearings that never work smoothly) but I can certainly check again... I might drive the car up to Napa to do a load test and check the price of a battery at the same time. I did just notice however that the water level is about 1" under the cutout so that may be a contributing factor for the battery performance... Edited October 25, 2018 by philipj (see edit history) Link to comment Share on other sites More sharing options...
Grimy Posted October 25, 2018 Share Posted October 25, 2018 8 minutes ago, philipj said: might drive the car up to Napa to do a load test and check the price of a battery at the same time. I did just notice however that the water level is about 1" under the cutout so that may be a contributing factor for the battery performance... If the plates are covered, best by a small (half-inch) margin, you're OK--don't overfill. Suggest you charge the battery to 6.3V before driving to have the battery load tested. Link to comment Share on other sites More sharing options...
philipj Posted October 25, 2018 Author Share Posted October 25, 2018 Ok, I just placed the trickle charger on the battery... It will be on at least until 11.00 or 12.pm, (for I do not like to leave it on overnight) then I will see the condition of the battery and go from there... In any case, I still would like to see at least 7 volts at high idle which I have never seen. 1 Link to comment Share on other sites More sharing options...
philipj Posted October 25, 2018 Author Share Posted October 25, 2018 (edited) I just watched an interesting video from Chrysler made in 1948 about voltage regulator adjusting. It mentions needing about 26 amps to run the car lights and radio. Here is why I think mine is out of adjustment. The time before last I run the battery down I jump started the car with my jeep on my way to get ice cream on a Sunday evening... Well, I got it going except that, shortly after turning the headlights on about 2 miles from home the car just quit! Done, dead as a doorknob; left me in the middle of an intersection with my 93-year-old mother in law (she loves the car!) sitting in the back seat !@#$! To this day I have never felt more shame or public humiliation! First time in 30 years that something like this has ever happened! Luckily for me, she never said a word, but in my head and to this day, all I see is a cotton ball puff of hair through the front and rear glass as I push the car with my brother in law off the road; flustered with embarrassment as to what she might be thinking! I had the car loaded with 5 people for a fun Sunday ride that never happened...;( And I still feel there is a problem that won't solve itself... First, the battery must be at full charge, then I need to figure out if the regulator needs adjusting and which one of the three coils within the regulator I need to change to increase the rate to about 7 volts or 20 amps minimum?... But how do I measure the amperage from the regulator? I may be overthinking the whole thing... Maybe I just should try to bring the charging rate up to 7 volts at least? If anyone has any other basic suggestions it would be great, before I get ahead of myself and think that the regulator really needs cleaning or adjusting... Edited October 25, 2018 by philipj (see edit history) Link to comment Share on other sites More sharing options...
MCHinson Posted October 25, 2018 Share Posted October 25, 2018 Make sure the water level is correct in the battery. Charge the battery fully with a battery charger. Have the battery load tested at a parts store. They can probably also test the generator for you. Replace the battery if bad. Do the same with the voltage regulator if bad. Drive the car. Don't leave stuff on to kill the battery while parked. If the battery is charging and not leaving you stranded, you are probably OK. You can have the Generator rebuilt if needed. Link to comment Share on other sites More sharing options...
Spinneyhill Posted October 25, 2018 Share Posted October 25, 2018 How old is the battery? Has it been left in a discharged state? Link to comment Share on other sites More sharing options...
philipj Posted October 25, 2018 Author Share Posted October 25, 2018 (edited) The battery is about 2 years old, It was discharged overnight or maybe 2 days to about 4 volts, at least 3 times within the last 2 months... I will have them do a load test tomorrow. Going through the car's paperwork I see that the generator was repaired in 2006 by Yesteryear Antique Auto Parts (Fl) with no specific information. I need a big fat note regarding the dash lights for the foreseeable future unless I am to disconnect it and run it through the headlight switch as suggested by Don M. Edited October 25, 2018 by philipj (see edit history) Link to comment Share on other sites More sharing options...
billorn Posted October 25, 2018 Share Posted October 25, 2018 26 amps for lights and radio seems like alot. Most early generators dont put out much more than that, leaving not much room for reserve. I still think you have a weak battery thats going bad. Sometimes they just go bad. Some sooner then others. I would start there. Pull it out and take it to the store and let them load test it even tho thats not 100% proof either way. Give it a good charge overnite if you think that will help. If the ammeter is showing a charge at 20 MPH then the generator is working. You can ground one of the posts on top of the generator to make it go to full charge and that will show you the generator is working. If the battery is weak the regulator should run the generator at almost wide open full charge to top it off and maybe for a long time if the battery is very low. I had one car where I thought the regulator was bad because it showed a strong charge all the time but it was just the battery going flat and not being charged up all the way and it was trying to charge it up and I just didnt give it enuf time. Dont be afraid to leave a battery on a trickle charger overnight. If your really worried put it outside on an extension cord or something but battery expolsions from trickle chargers are rare. Get it 100% charged and then test. A bad battery might even show it is 100% charged but it wont be. There is an easy fix not a hard one. But now I see we are going to go down the rabbit hole again like we always do and try to make it some complicated weird uncommon problem when the most likely explanation is that you're battery is low it has never charged up all the way and it is now weak and your generator is working overtime to top it off. If anything you're regulator might be set too low but you can adjust that if you have problems later. But I will bet 5 bucks its just a bad battery that went flat one times to many. Dont make it to complicated. Charge up the battery and do a load test. Or just buy a new one and see if the problem goes away. A battery is only $100 bucks and it never hurts to have a spare around charged up and ready to go. Battery. Then everything else. Dont overthink. Dont let too much info distract you. Simple machine simple solution. Link to comment Share on other sites More sharing options...
philipj Posted October 25, 2018 Author Share Posted October 25, 2018 You are absolutely right my friend, unfortunately, I tend to overthink things sometimes, forgetting that these are simple systems. I will certainly start with the battery and let it charge overnight... Thank you for the sound advice. 1 Link to comment Share on other sites More sharing options...
TerryB Posted October 25, 2018 Share Posted October 25, 2018 If you have a shop manual and / or a Motors Repair manual it can help you with adjusting your regulator should that be necessary. The battery load test can be a great help in deciding what your next step should be. 1 Link to comment Share on other sites More sharing options...
BuickBob49 Posted October 26, 2018 Share Posted October 26, 2018 When I purchased my 39 Roadmaster a few years ago, it had one of those screw-down cutoff things on the negative battery post. I always experienced slow turnover when starting the car, especially so on hot days. I first thought it was simply starter drag with the big 320 engine, or a bad battery. The battery was fine. I cleaned the posts and cutoff hardware with no change. One day, the car died at an intersection. How embarrassing! (It ran so quietly that I didn't know that it had died.) Shortly, I removed the battery cutoff hardware. No more drag and no more dead car. The 320 engine now spins about as fast as my 49 Super with the 248 engine! My wiring harness is new on the Roadmaster. I have no concerns about leaving it live between uses without a cutoff. I have no discharge issues. 1 Link to comment Share on other sites More sharing options...
TerryB Posted October 26, 2018 Share Posted October 26, 2018 I had easy access to a tune up specification book last night so I looked up Buick charging rates. The book only goes back to 1946 but the 6 volt systems listed had charging rates of about 7.3 volts. No engine speed was listed for this voltage but at least it gives you a ballpark idea of typical charging volts. Link to comment Share on other sites More sharing options...
philipj Posted October 26, 2018 Author Share Posted October 26, 2018 Here is the skinny regarding the battery condition as of this morning after a full charge overnight...6.26 volts at rest. Shortly after starting the car it went to 6.34 and as it warmed up it went to 6.82 for a short time... After the vehicle was warm it went anywhere from 6.34 at idle to 6.48 about 900-1000 rpm... Before checking it with the meter I tested the specific gravity and I got "Average" on all three cells. It seems that my battery might be on its way out, unless I can charge it more than 12 hrs and see what happens... Now, given the battery condition, does it interfere with the ability of the regulator to allow a charge higher than 6.82 volts, or should I be looking elsewhere? Link to comment Share on other sites More sharing options...
MCHinson Posted October 26, 2018 Share Posted October 26, 2018 You are overthinking again. Does it start the car routinely or do you find yourself stranded due to the battery dying? If it shows over 6 volts on a meter and it starts the car, it is OK. If you want to do more testing, have the battery load tested at an autoparts store as previously discussed multiple times in this discussion. Link to comment Share on other sites More sharing options...
Spinneyhill Posted October 26, 2018 Share Posted October 26, 2018 In my experience, overnight on a trickle charger is nowhere near enough. It depends on the size of the trickle of course and how smart your trickle charger is. It might also depend on whether you have a lead-acid or AGM or Calcium battery: they need different charging voltage. I had an odd problem with my 1939 Studebaker more than 25 years ago. After a lot of head scratching (I was completely ignorant of these things) I discovered it was caused by the earth being on the negative rather than the positive terminal. Once I set that up correctly, it took more than 100 miles before the ammeter dropped back to just a trickle on the + charge side while driving. Perhaps take it for a 100 mile drive! Link to comment Share on other sites More sharing options...
TerryB Posted October 27, 2018 Share Posted October 27, 2018 (edited) With no load on the generator other than the couple of amps required to operate the ignition coil when the engine is running, the battery voltage is adequate ( my opinion). I would suggest a simple battery load test by turning on the headlights and repeating your voltage test at idle and fast idle. This should make the charging system work harder and you can see if you get to 7 or more volts. The ultimate load test is to turn lights on to high beam and your heater fan to get maxim load on the electrical system. Under this condition you can see if the battery plus the car’s charging system can maintain greater than 6.3v. With this test you will have to be running above idle speed. Generators are not too efficient at low speed operation. Your battery seemed to recover well after starting the car so I don’t think it’s doomed. Starting requires a lot of energy draw on the battery and a weak battery will need a longer time to return to the 6.3v level. Yours did not seem to show this. Before you do my test, see what the battery is at rest before starting. Just want to insure it is holding its charge. Edited October 27, 2018 by TerryB (see edit history) Link to comment Share on other sites More sharing options...
Jack Worstell Posted October 31, 2018 Share Posted October 31, 2018 I don't think a shop can do an accurate load test on a battery that is partially discharged...it has to be fully charged or close to it to get a good test. This is what the shops have always told me. ( ask your shop to confirm this or refute it for a double check) A fully charged ( or nearly so ) battery at rest will show about 6.3 amps. If partially discharged it will show lower volts...maybe much lower depending on the degree of discharge. With the engine running ( maybe 1000rpm or better ) with a good battery good generator and good regulator you should see maybe 7.3 volts IF you don't have a lot of load turned on and IF the battery is in a good state of charge. If a lot of load is turned on and/or the battery is partially discharged...voltage will be lower...maybe much lower. A lot of load and/or battery partially discharge will always pull down system voltage...……. maybe a little ……..maybe a lot....depending on the amount of load and the level of discharge The regulator will always try to hold voltage constant and usually it will hold voltage almost constant over a range of conditions...but it has limits Jack Worstell jlwmaster@aol.com Link to comment Share on other sites More sharing options...
philipj Posted April 25, 2022 Author Share Posted April 25, 2022 Hello friends, Since I am now driving the car again after a torque tube repair and tires, I find that I am still being haunted by charging system (generator) problems... The newest thing I discovered is a bearing noise on both ends, and discharging as soon as it gets very hot (By that I mean 190 F. from a 20-minute idle in queue to get into a car show yesterday) which prompted me to look at the model of the unit 1100004 (7L1) which is not the correct generator to start with for the car... I believe that it belongs to a Chevrolet Master! The unit is only putting out about 6.3 volts at best, either at high iddle or 800 rpm.. If I did not keep my battery on a tender, I would have been in real trouble yesterday...;( The questions I have are... 1- Is Delco 1101052 the same generator as a Delco 52 U... 2- Is part of my problem (aside from incorrect/faulty generator) a miss adjusted voltage regulator? or just dirty contacts? Aside from that, I hope that the Delco 1100004 is the same length as the correct generator, so I won't have to chase a mounting bracket... Lastly, does anyone have a rebuilt Delco 1101052 they can part with? Thank you... Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted April 25, 2022 Share Posted April 25, 2022 If you have the right regulator for the 38s, follow the procedure in the shop manual to set voltage. It should be about 7 vdc. Cheers Dave Link to comment Share on other sites More sharing options...
philipj Posted April 26, 2022 Author Share Posted April 26, 2022 I have a 1118213 regulator, but unfortunately no shop manual yet... The current generator is noisy and does not give more than 6.30 volts... Anything on my question regarding the generator options? Thank you. Link to comment Share on other sites More sharing options...
MCHinson Posted April 26, 2022 Share Posted April 26, 2022 9 hours ago, philipj said: 1- Is Delco 1101052 the same generator as a Delco 52 U... Under GENERATOR, Complete The parts manual indicates that the original 1938 & 1939 40 Series Generator was #1101052. The original Generator for the 1938 & 1939 Series 60 Generator was part number 1101053 (but the manual indicates to "Order 1101052") The original Generator for the 1938 & 1939 Series 80 &90 was part number 1101055 (but the parts manual indicates to "Order 1101052"). The next section lists "EXCHANGE GENERATORS" 52U is the echange generator listed for all 1938 and 1939 Buicks. The List price on the 52U is $17.80 which was the same price listed for the 1101052. The Exchange price for the 52U was $9.50. From what I see in the parts manual, I would say that the 52U is probably identical to 1101052, but even if there is some difference, they are both compatible with any 1938 or 1939 Buick. I would encourage you to get the correct Generator and get a 1938 Shop Manual. Dave Tacheny probably has the Generator that you need. Ebay or Bob's Automobila should have the Shop Manual that you need, either an original or a reproduction Manual will be fine for your needs. 1 Link to comment Share on other sites More sharing options...
philipj Posted April 26, 2022 Author Share Posted April 26, 2022 (edited) Hello Matthew, I thank you for your input which is always appreciated... Going over the 29-41 parts book, I found your information, but I had no details on the exchange unit, just some questions... You have confirmed that it is safe to use a Delco 52 U unit, and luckily, I just picked one up on Ebay... I am happy to know that it is one option and correct for the vehicle... Next on my list is a service manual, which will be certainly useful... Edited April 26, 2022 by philipj (see edit history) Link to comment Share on other sites More sharing options...
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