34 V8 Generator questions

ctvpa

ctvpa

Senior Member
Greetings.
I am normally a Model A guy, but recently purchased a 34 V8. The car has been in storage for many years, but is in outstanding condition with 46,000 original miles.
I tested things out and found my output from my generator was quite weak. I sent it to a shop in California for a $$ rebuild.
I received it back yesterday and installed it today. I have a brand new quality cutout. When I power upped the engine, I had my volt meter - on the output and + on the ground. When I started the motor I got negative reading, so I swapped the connections and put the + on the output of the generator, and the - on the ground I am showing 13-14 volts. I shut everything down right away.
My questions are,
1) Did they do an error in the rebuild?
2) Am I checking this wrong?
3) It ran for about 2 minutes, did I do any damage?
4) why would a professional antique auto restoration company, use plastic wires with compression fasteners rather than period correct looking modern wires and connectors?

Thank you,
Craig
 
A three brush generator shouldn't put out more than 7.5 volts the way they are configured. There are folks who convert these things to 12-volt single wire alternators though so be sure that didn't happen. A short run with double voltage out put shouldn't have hurt anything. If it is still configured as a 3-brush generator, you might look at the brushes & internal wiring and make certain there are no wires or through terminals that are not properly insulated from other connections or the frame. Many of the newer cut outs are just a diode that allows out put current to pass to the buss but won't allow battery current from the buss back in after shut down. The OEM ones are switched closed by the generator out put from the residual magnetism in the field pole shoes to get started. The gen also might need to be polarized for positive ground if it has no residual magnetism in the field pole shoes.
 
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ctvpa,have you tried moving the third brush down in the generator to decrease the out put? I know you said that your a Model A guy,so I assume you know about the adjustable third brush.I hope this helps.E.P.W.
 
epw1949 said:
ctvpa,have you tried moving the third brush down in the generator to decrease the out put? I know you said that your a Model A guy,so I assume you know about the adjustable third brush.I hope this helps.E.P.W.
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Yes, I am aware of the adjustment. But when I saw 14 volts, I just shut down the car for fear that much voltage to a six volt system would damage something. I thought that the 3rd arm mostly amperage, not voltage. Then there is the issue of it is putting out + from the generator output.
But I am open any Ideas, Thank you
 
Have you fitted a battery into the circuit? Or are you simply reading the output without the other terminal on the cutout being wired into the circuit?
 
Hi There, Firstly it seems the restoration shop may have tested or ran up the generator in their test bench connected negative ground instead of positive ground which your 34 ford should be. Easy fixed by doing a quick connection with the generator negative power wire onto the generator output wire coming out of the top of the gen. You will get a small spark here. Should be a earth wire here also which goes under one of the cutout mounting screws. But before you do that please be more specific about that new cutout. What was wrong with the old cutout ?? Its the very best one you could have on your generator. Most of the new repro cutouts are absolute junk. How do you know yours is a quality one ? Does it have a diode in it ? If so it has to be a POS ground cutout. Or it might have an electronic regulator inside ?? Get back to me before you play around with anything with full details of this and I can maybe help you. Contact that restoration shop and ask these questions and get your old round cutout back if they have it still. Regards, Kevin.
 
Brian said:
Have you fitted a battery into the circuit? Or are you simply reading the output without the other terminal on the cutout being wired into the circuit?
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I have done both. When I first started the car the battery was involved. Then once I noticed the excessive voltage I disconnected the cutout. I connected my voltmeter (-) to the output, (+) to the ground and my meter went to the left, below 0. When I reversed it I got 13 volts.
 
First off I would suggest you contact the rebuilder to find out exactly what they did. I'm pretty sure they sent an invoice but sometimes the invoice doesn't state in detail what was done.
Have you polarized the generator as Rotorwrench suggests?
 
B-O-B said:
First off I would suggest you contact the rebuilder to find out exactly what they did. I'm pretty sure they sent an invoice but sometimes the invoice doesn't state in detail what was done.
Have you polarized the generator as Rotorwrench suggests?
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Yes, I have contacted the rebuilder, and will wait for their input before I do anything. The paperwork all says 6v+ground. I am building up information for when I talk to them I will know a bit of information. But they are not open Christmas eve & day. So I took this time to reach out for ideas.

I am concerned, why would a company that specializes in rebuilding classic and antique auto's would not use period looking wire and connectors. I have plastic coated wire, with pressed plastic crimped connectors.

I sent it to this rebuilder because of 'Barners' suggestion.
 
Hi Again, when you send something out for repair/rebuild you need to keep control of the job and what they are doing. YOU need to spell out what your expectations are and not just leave it up to them (to stuff it up for you). Most auto electrical shops just don't understand what originality is or means and so just do a modern style job on it as in plastic wire, modern crimp terminals and so on. The restoration shop you sent it to may have sub contracted the job to someone else. Very hard now to find an electrical shop who care about these things. As I said get back to me when you have some answers and I will try to guide you. Regards, Kevin.
 
UPDATE !
Even though I did an email order for a 6v +g rebuild &
I send an printed out order form for a 6v +g rebuild &
I sent a letter with the unit 6v +g rebuild &
They called me to confirm 6v +g rebuild &
They marked the unit 6v +g rebuild

They did a 12 volt rebuild. I have to send it back. I don't think I should have to pay, $50 each way to them. Regarding using period cloth covered wire, I was told it is too expensive (.25/foot at Snyders) and not curreltly available.
 
Bruce in southern OH said:
What is name of shop you sent the Generator to, I would like to know, may save others or myself problem in future, thanks
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I got the name when I posted for the best shop here on the Barn. If they give me any problem I will post their name in big bold letters, OFTEN.

I will keep you posted, Thanks for the support.
 
UPDATE 1/26/14

Well gentlemen, as you know I sent a 6v+g generator rebuilt.
They sent a 12v +g back. (With their own inventory tag listing it as a 6v+g)

They tried to tell me that this is MY fault, that I sent them a 12 volt.
The car is original with 40k miles, it won a Classic Car Club National First. I really doubt the wrong generator is in it.

I complained and they offered to correct it.
I sent the generator back, with all the information attached to it. I got my new one,,,,,,,, 12 volt - Ground !
I just cannot believe it.

The company is C&G Ford Parts http://cgfordparts.com/ from Escondido, Ca.
I am so frustrated !
 
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