1937 Cadillac Charging System Problem

[Zachary Lamberti]

Gentlemen,

The latest obstacle I have encountered in getting my 1937 Series 75 Cadillac back on the road is a problem in the charging system.  I have checked all of the obvious culprits, i.e. generator output, electrical connections, etc. and now believe the issue to be somewhere within the voltage regulator, which happens to be a six terminal Delco-Remy Model 5818. 

Can anybody offer advice on how to troubleshoot the voltage regulator itself or provide any specs to adjust this particular unit (#5818) ?

As always, your help is greatly appreciated.

I could have never made it this far without all of the help provided through the users of this forum!  Truly a great resource.

Thanks in advance,

Zachary Lamberti   

[Steve Passmore]

best to replace it with a new unit I would have thought Zachary, they come up on eBay quite often.

[harvey b]

Hi Zach, has your car been rewired?,or is it the original wiring in it,i had a similar problem with my 37,we rewired it our selves using the old harness as a pattern,was a lot of work but it looked good when we were done,i couldnt get the battery to charge,guage was moving like it should,generator was rebuilt and was putting out the right voltage?,i fougt with it for 2 summers and still no luck,i did find a guy who set up the regulator and generator off of the car,he was 90 years old and really knew his stuff,when he gave them back to me he had a little wiring diagram on the generator,it seems i had 2 wires switched,all my charge was not going any where,they were the load and feild wires i think?,went home and switched it around,car now works great and charges like it should.i used a different regulator on my car,it is for some type of farm tractor,it does have the 5 terminals on it like the original does,the regulator you have the 5818 is for a 38 caddy,37s use a 5817 model,not sure what the difference is,i can get you the number from mine if you want to try one of them?HTH  Harvey b

Harvey Bowness
65 Dougan Lane
P.E.I.
Canada

[william_b_noble]

so, can you post some numbers and specific measurements?  What is the generator output voltage at idle, and at 1000 RPM or so.  What is the field voltage, what is the battery voltage at each of those conditions.  What does the ammeter do.  With the top off, what is the regulator doing?  Did you polarize the generator?  do you have the 37 shop manual available?  (I have the manual for my 36, bought a repro from crank-n-hope, decades ago)

[Zachary Lamberti]

Thank you both for the replys.  Car has been rewired with original type harness back in the early 70's.  It will take some time before I can get specific information William, but I will try to work on that over the next few days and will post what I find.

Will get to work and be back in touch.

Thanks,

Zach

[Wayne Womble 12210]

I have a Motor manual about `37 that has the adjustments and service procedures for several types of regulators. The nearest I could find to that number is #5807.  I would think it is similar in construction. I could scan it if necessary.

[Doug Houston]

On Cadillac's major series from mid-thirties through 1939, a rather complex generator regulator is used. It regulated Voltage and current, wit the usual cutout relay, and a starter cutout relay. Calibration and service on these regulators is not for the faint hearted. There are automotive electrical shops that can handle the service for the regulators, and you need to know who they are and if they can handle the job... not from their claims, but from an indorsement from someone who can vouch for their competence. 

These regulators go for mighty big bucks, if you can find one. You won't find a new one (though miracles can happen, but don't count on them).  It may be possible to replace the regulator with one from a '40 through '42 Cadillac model, but I'd have to do a lot of testing and measuring before I'd be satisfied that I was right.

I have two of them myself, on Cadilac 90's, and they work fine. I just say prayers that they'll leep going.

[Zachary Lamberti]

Thank you very much Wayne and Doug for the information. 

Wayne, if it isn't too much trouble, I would be interested in seeing a copy of your service and adjustment procedures as I am currently flying blind without a manual myself.

And Doug, I would really like to retain the original unit if at all possible, and therefore need to find a competent shop or individual I can trust to handle the job...any recommendations?

Thanks again for your help.

Zachary   

[John Washburn CLC 1067 Sadly deceased.]

Zack,

We have found an old guy who can rebuild these Voltage Regulators, correctly the first time.

He has rebuild two of my regulators off the 37 LaSalle, 5 post and both work as new. Brad Ibsen had one of his done also.

Drop me a note if you want his info. Great buy.

the johnny

[Zachary Lamberti]

John,

Thank you very much and Yes, I would definitely like to get his contact information. 

I really appreciate it.   

Zachary Lamberti