39 generator
 

My 39 deluxe generator has 3 terminals, two on the side and one on back. Back one is armature, one side one is marked field and the other one is not marked. The harness has two wires, one for field and one for armature. What goes to the other terminal? Gen. Is a two brush and car has a voltage reg. Gen. in my reference manual does not show this third terminal. Mark

Re: 39 generator
 

on later field housings that post is a ground wire to connect to the regulator to eliminate weak ground errors in voltage

Re: 39 generator
 

Thanks, I was hoping it was a ground but was thinking gen. is grounded to engine.

Re: 39 generator
 

A lot of the early regulators were mounted on rubber cushions to isolate them from outside vibration sources. The engineers were likely worried that outside vibrations might affect the vibrating nature of the voltage regulator and current limiter poles of these relatively new devices. The cushion mounting made external grounding a necessary thing.

Re: 39 generator
 

You don't have a '39 generator.
The terminal on your later unit that isn't marked is a ground.

Re: 39 generator
 

As Kube mentions above the 39 two brush generator has two terminals. The ground terminal was added in later years. There is a date code stamped into the body of the generator. The ground for the body isolated regulator was made by a flexible 3" wire strap between the regulator body and one of the regulator mounting screws.

Re: 39 generator
 

There is a Letter code near the Ford script on the case. My 40 generators have a U and I believe the 39s have a T. Probably early 40s could have a T also. We all know who has the definitive answer to this and may chime in here!
I might be remembering wrong but I think I read somewhere the 39 standards still had a cutout and the deluxe cars had a voltage regulator. Not sure about this. I haven't owned a 39.

Re: 39 generator
 

As Deuce has rightfully advised, '39 generators had a "T" stamped in the body, '40 generators had a "U". No doubt some '39 generators found themselves installed in early '40 models.
I no longer recall exactly when in 1939 that all models went to a voltage regulator. I could look it up in my records if someone really needed that information.
Many "standard" models received a regulator on the assembly line. It was thought this was radio equipped cars only. I've never found any supporting evidence of that. Also, I've had a few extremely well preserve 39 standards that had voltage regulators and no radio.
I'm not confident we will ever know exactly which models got a regulator
and when and / or why.

Re: 39 generator
 

The gen.i am using has a V-4 after the script. The one that came on this engine has a C-11 after the Ford script. This is a truck gen. and has the third post also.

Re: 39 generator
 

V4 = April, 1941 manufacture.

I'm not certain what the C equates to in manufacture year.

There's absolutely nothing wrong with using the later gen. on your '39. There's no need to hook up the ground post. Just be certain there is no paint on the mating surfaces of the generator / intake manifold.