Generator/regulator i.d. from photo

ccaissie

Member
Can someone identify this type of generator /regulator setup on a 1948 A-V?

System suddenly won't charge and I need to know what I'm dealing with.

Thanks,
Colin
a157672.jpg

a157673.jpg
 
Colin - Looks like an aftermarket solid state cutout.

A couple tests:

1 - With the engine running half-throttle or faster, jumper the two cutout posts together with #12 or heavier wire (expect a spark when you connect!). If the ammeter shows a charge with jumper connected the cutout is shot.

2 - Disconnect both wires from the cutout. Now take a VOM or DMM and measure the resistance between the two posts in both directions. A good cutout will show infinite resistance one direction and nearly 0 resistance the other. (If resistance is infinite (or 0) in both directions the cutout is bad.)

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Your OEM wiring looks pretty tatty. A new wiring harness - either purchased or home-made - would be a good investment!
 
Right! The wires had been upgraded after this photo. I'll run these tests. I notice that the field wire is permanently attached to the case, and the generator wire shows 15-20volts at idle.

Normal behavior?

C
 
Kinda normal!
You have (probably) a 3 brush generator. It has been wired for full output all the time. (third brush location on the commutator is adjustable to manually regulate charge rate)
If the device shown is a solid state cutout, as Bob M is indicating, and I agree, and if it is "open" meaning it is basically a burnt out light bulb, the voltage will be that high because the gen is mot loaded.
The best solution for battery life is to use a voltage regulator (two regulating devices inside, one is a cutout, the other controls the grounding of the field to assure correct battery charging)
The third brush is moved all the way toward the fixed brush as far as it will go.
The Field terminal on the gen (now grounded) is hooked to the F terminal on the regulator.
The Arm terminal on the regulator (it might say GEN on it) is connected to the Arm terminal on the Generator (now connected to the existing cutout)
THe Bat terminal on the new regulator is connected to the wire now connected top the other end of the bad cutout.
No other connections are needed.
Make sure the new regulator is grounded to the tractor or generator it must be a clean and shiny connection to ground through its mount.
It should be good to go. Jim
 
Colin - 15 - 20 volts at the genny ARM terminal while idling says the generator is OK but that the cutout has "failed open" (infinite resistance).

Jim's advice to replace with a voltage regulator is right on. Do this and your battery will thank you with longer life and more reliable starting!
 
Tag should be there next to the block. It should be either a 1101423 or 1101355 as those are the two gens used in that era with cut-out mounted on top there are some cut-outs on the market like yours or it could be smoe solid state things anyhow the field is grounded thus hi-out put. Make sure when you get a new regulator get one that is made for you gen # pos gnd they are out there last one i got was from Car Quest made in USA you weont need the wire from the field going to the lite sw. Get your reg from a Delco or good dealer not one size fite all.
 

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