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russcc 09-18-2014 05:21 AM

8RT charging system trouble shoot
 

The 12V 8RT charging system is not working. Had the generator bench tested at the auto electric shop, putting out 35 amps. Polarized the generator and regulator. Grounded the generator G to the regulator.
Went through the following steps;
1. With the engine at high idle, pulled the positive battery cable, engine quits.
2. Grounded the field F on the generator to go on full charge, pulled the positive battery cable, engine quits.
3. Grounded the field F on the regulator to go on full charge, pulled the positive battery cable, engine quits.
4. No change in the ammeter under full charge, stays right in the center and does not move.
5. Have 13 volts on both sides of the ammeter.
6. By passed the ammeter, grounded the field F on the regulator to go on full charge, pulled the positive battery cable, engine quits.
7. Have 12 volts at the BAT terminal on the regulator.
8. have continuity on ground wire from generator G to regulator ground.
Suggestions please. Thank you.

jailhousebob 09-18-2014 06:48 AM

Re: 8RT charging system trouble shoot
 

Was this a working system that just stopped working or a new installation of one or more components and wiring ? How is the regulator being grounded? Make sure the regulator frame has a good ground by using a bonding strap or wire from one of the mounting bolts to a ground known to be good. Bob

chap52 09-18-2014 07:13 AM

Re: 8RT charging system trouble shoot
 

Had a similar problem. Pulled the alternator and had it bench tested three times...Okay
Ended up my not too old battery was the problem???

russcc 09-18-2014 08:56 AM

Re: 8RT charging system trouble shoot
 

Thank you for the help. Good points.
This is a new system in a roadster I wired myself. We know the generator is good.
A good source told me I polarized the regulator wrong, so that could be it as everything else checks out ok. Battery is right up to snuff.
I was advised to polarize the regulator, you take off the field wire, and momentarily BAT term to Armature terminal on the regulator. Will report back. Thank you

Bob C 09-18-2014 11:33 AM

Re: 8RT charging system trouble shoot
 

You don't polarize the regulator, just the generator.

Bob

rotorwrench 09-18-2014 12:15 PM

Re: 8RT charging system trouble shoot
 

12-volt indicates a different than stock generator. The 12-volt stuff was introduced on pickups & light trucks in 1956 along with the cars. I am curious what sort of generator you have or what modifications it has?

Positive or negative ground has a big effect on polarity. As was mentioned you only flash the field to add to magnetism to the field pole shoes so that the generator can pull the cut out and bring the generator on line when the thing starts rotating at start up. The cut out pole is inside the regulator housing if you have a three pole 12-volt regulator as was introduced in 1956.

If you have an alternator inside a generator case, then there is enough difference that all the generator stuff is irrelevant. It would then have either and internal solid state regulator or possibly an external 2-pole type.

supereal 09-18-2014 01:38 PM

Re: 8RT charging system trouble shoot
 

The best way to check to see if the charging system is working is to put a voltmeter across the battery posts, then turn on the headlights and rev the engine. You should see the voltage rise and fall if the charging system is working. I'd suspect that there is a glitch in your new wiring if pulling the battery cable shuts the engine down.

scooder 09-18-2014 01:39 PM

Re: 8RT charging system trouble shoot
 

Is it a Ford generator and regulator? Different makes use different setups, and are wired/grounded differently.
Martin.

russcc 09-18-2014 06:48 PM

Re: 8RT charging system trouble shoot
 

Thank you fans. Solved the problem with Ray Helgers's expert advice. I got the NOS, USA made regulator & '56 Ford generator from Ray which I used to convert the 6V to 12V, negative ground. Ray straightened me out on the correct way to polarize the regulator. 1st, remove the field wire from the regulator, then with a jumper from the BAT or battery terminal of the regulator to the GEN or generator/armature terminal, connect the two momentarily to polarize it. That done, it will would still not charge with the engine at high idle, no change on the ammeter, and the engine would quit when you shut off the battery switch. Took the cover off the regulator, and closed the main points to the battery terminal by hand. Bingo, the ammeter registered plus 15V. But it would not pull in by itself. Ray suggested cleaning the points on the other 2 relays. Sure enough they were slightly corroded, so I clean them lightly with 220 paper . Restart the engine and another bingo. Main relay pulls in, ammeter goes to 15V, checked voltage at battery, got 13-15V, shut off the battery switch and the engine kept running. Moral of the story, smart friends and dirty points.


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