How to polarize generator - 1939 DeSoto

[mike39desoto]

Hi all - new to the forum. I have a 1939 Desoto Opera Coupe that I bought when I was 13 (I'm now 47 LOL).  I had the generator rebuilt years ago but it's never worked.  I'm guessing it may not have been polarized and I'm not sure how to do this safely.  I have a replacement voltage regulator but am thinking I should make sure the generator is properly polarized first.  All wiring is original and in good shape and car is still 6v positive ground.  

[Don Coatney]

This may or may not help.

 

 

[mike39desoto]

Thanks Don.  Definitely helps.  Problem is i'm not sure which post is which?  This is an original regulator and nothing is stamped on the terminals unfortunately.  I 'think' the lead on the left side is Battery as it goes to the horn.  Not sure which is which on the right (driver) side?  All diagrams show all three wires on one side of regulator.  Thanks in advance 

[DJ194950]

Look for labels to terminals on the regulator cover.

 

If not available use a test light to determine the battery terminal for a constant hot. Quickly(flash) touch that terminal with a jumper wire to the middle terminal, done!

 

DJ

[John Reddie]

Kudos to you for keeping your DeSoto for all these years. I so wish I had done that with some of my vintage gems back in the day.?

John R

[mike39desoto]

Thanks Don.  Definitely helps.  Problem is i'm not sure which post is which?  This is an original regulator and nothing is stamped on the terminals unfortunately.  I 'think' the lead on the left side is Battery as it goes to the horn.  Not sure which is which on the right (driver) side?  All diagrams show all three wires on one side of regulator.  Thanks in advance 

[mike39desoto]

Sorry - somehow posted reply 2x.  Thanks DJ - will test it tonight and @ John. I  had to sell it 2x to get through college and grad school and then buy it back, so that car has cost me plenty but it was my first car and I'm glad i still have it.  Looking forward to getting back on the road.

 

Thanks all for your help.

 

[DrDoctor]

 .

Edited December 20, 2018 by DrDoctor

[Plymouthy Adams]

getting back a car  you once owned is not always possible.  I sold the very first car that I built from scratch as they say....having gone through the entire car in and out and owning it for a few years only to sell it against my father's wishes to loan me the money instead.  But, that is another story...over 28 years later on the internet one night I saw this car listed for sale.  I made contact, spoke with the owner and after telling him everything bout the car and how it was built, his wife state that the car WAS to go back to me, so I was able to get my car back.  Still running but in need of some work....just happy to have Madeline back to the house with me...the name has a history also.

[Sharps40]

 

http://www.automotivetimelines.com/blog/2017/09/06/polarizing-a-generator/

[Dodgeb4ya]

On 11/26/2018 at 12:59 PM, mike39desoto said:

Thanks Don.  Definitely helps.  Problem is i'm not sure which post is which?  This is an original regulator and nothing is stamped on the terminals unfortunately.  I 'think' the lead on the left side is Battery as it goes to the horn.  Not sure which is which on the right (driver) side?  All diagrams show all three wires on one side of regulator.  Thanks in advance 

Momentarily touch the "BAT to the "ARM"......as mentioned above...the left and Rt lower wires on your regulator... best I can see

Both the Bat and the Arm wires on the regulator will be 10 gauge....being the  thicker wires of the three on the regulator.   

The BAT is a 10Ga. black and the Arm is 10 Ga. red.  Do not touch the third thinner 16 Ga. green "field" wire. . the colors can be seen very lightly scraping the cloth covering.

Use those wires to polarize the Autolite generator used on most old MoPar cars.

 

[DJ194950]

Years ago I saw one voltage regulator that the only markings of the terminals were Under the the current wire terminals that your wire is connected/crimped.

Try removing one connection to check for that?

 

Just a long shot, but.??

 

dj