I just bought a 62 f100 4x4 292. And the generator light stays on when running and volt meter shows a drop in voltage from 12.5 to 12.3 when running. I put new brushes on it and still no change. So I pulled back out. I think the field and grd may have been hooked up wrong now looking at a wireing diagram. With generator out I hooked up a jumper from +batt to arm and from grd on gen to -grd on batt. And generator takes of spinning I think this is called motoring the gen? Does this mean the gen is good? Is there other tests I can run to make shure its good before putting back in.

 

normally but not always if a generator motors it will charge

 

Did you replace the regulator? I remember when you put in a regulator, it has to be "polarized" by jumping a wire across the top and bottom connections on the regulator. I don't remember if you have to do this with a gen. rebuild.

 

Yes - It needs to be polarized.

 

I put the generator back in and put different a regulator in off a different truck that was working when parked and flashed the fld wire over to the batt wire on the reg. Which the reg has printed on it to polorize it and still is not charging . The arm treminal on the reg only shows 2v when you rev the motor. The fld shows 0v and the batt shows 12.3 when reved? Also the the wires were crossed I put them on the right way and put new ends on them.

 

Could I have polarized it wrong is there another way?

 

To polarize the generator, simply make a short jumper wire to short between the battery (b or bat) and generator (g or gen) lugs on the cutout relay or voltage regulator. Only a split-second or a spark is required, so simply tap your jumper wire onto the lugs and pull them right back off

 

Just tryed it the way you said and still nothing, I found a diagram to test generator output u disconnect the arm and field on gen. Then u run a jumper from one to the other. Start engine and connect a amp meter from the arm term and the other to batt and u should get around 30 amps I got zero. I think the field coils must be shorted out.

 

you must have field current from regulator to generator or it will not charge.should be four wires on reg. (1) ign should have 12 volt with key on(key switch wire) (2) F .this one goes to field termial (F) on generator (3) battery --should be 12 volts with engine off.
(4) A goes to A wire on generator(generator output)

With wires unhooked from generator Try grounding the A wire on the gen with the engine running You should get a slight spark --if it will not spark generator is bad.
.AlSO Generators can motor and not charge.I've been in the rebuilding business for twenty+ years and have crossed this bridge before.

 

Do this with the engine running.....

To polarize the generator, simply make a short jumper wire to short between the battery (b or bat) and generator (g or gen) lugs on the cutout relay or voltage regulator. Only a split-second or a spark is required, so simply tap your jumper wire onto the lugs and pull them right back off

 

Tried polarizing with engine running with a jumper still did not work . Have not tried grounding the arm wire yet. Starting to think I would be better off converting to a alternator?

 

You would be,more dependable,much simpler.If you can find a rebuild shop in your area ask them for a 7127se.this is an old style delco alternator with a built in regulator.This alternator ( Must be S.E.)will turn itself off and on automatically.All you have to do is hook one wire (usually comes from positive post on battery)to the output post on the back of unit.
When you start you motor the alternator will self excite and start charging and will turn itself off when engine is shut down.
The conversion itself is not hard to do.One of the main advantages of the alternator is the amperage output.The generator on its best day will only charge about 15-20 amps.The delco alternator should be around 55 amps.

 

Ok thanks for the info. I think I am going to go with the alternator.

 

I have a ford f100 6 cylinder,iam having problems with the voltage regulator or something. I bought new alt. and regulator,had it tested and barley charging.Iam thinking in the wiring,but i bought new fuseable links. Even the auto place was confused,lol. Any sugessions?

 

I would check and make sure the ground is getting a good connection. And check all the wires on the alt and the regulator, where all the connectors are. Sometimes they look good but are only hanging on by a wire or two.