The Ford Barn

russcc · 09-18-2014, 05:21 AM

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

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

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

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

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

Bob

rotorwrench · 09-18-2014, 12:15 PM

Sponsored Links (Register now to hide all advertisements)

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

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

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

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.

09-18-2014, 05:21 AM	#1
russcc Senior Member Join Date: May 2010 Posts: 2,871	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.

09-18-2014, 06:48 AM	#2
jailhousebob Senior Member Join Date: May 2010 Posts: 143	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

09-18-2014, 07:13 AM	#3
chap52 Senior Member Join Date: Jun 2013 Location: Marana Arizona Posts: 1,829	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???

09-18-2014, 08:56 AM	#4
russcc Senior Member Join Date: May 2010 Posts: 2,871	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

09-18-2014, 11:33 AM	#5
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 9,360	Re: 8RT charging system trouble shoot You don't polarize the regulator, just the generator. Bob

09-18-2014, 12:15 PM	#6
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 17,410	Re: 8RT charging system trouble shoot Sponsored Links (Register now to hide all advertisements) 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.

09-18-2014, 01:38 PM	#7
supereal Senior Member Join Date: Jul 2014 Location: Iowa Posts: 1,634	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.

09-18-2014, 01:39 PM	#8
scooder Senior Member Join Date: Jul 2010 Posts: 2,595	Re: 8RT charging system trouble shoot Is it a Ford generator and regulator? Different makes use different setups, and are wired/grounded differently. Martin.

09-18-2014, 06:48 PM	#9
russcc Senior Member Join Date: May 2010 Posts: 2,871	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.