Alternator problem

[Johnnydidd]

New alternator, 1 wire, 12.9 volts when not running, running 12.3 volts, no output. Do you think its the alternator?

[V8 Bob]

Originally Posted by Johnnydidd

New alternator, 1 wire, 12.9 volts when not running, running 12.3 volts, no output. Do you think its the alternator?

One wire alternators require around a 1000 or more rpm rev to excite and start operating, but if you have performed that, the alternator is probably at fault.

[Tony, NY]

like V8Bob says. Punch the throttle once and the gauge should show charging. I had a one wire rebuilt last year and the shop suggested I go to 2 or 3 wire, what ever they normally are.

[Model A Bill]

I had a new 1 wire alternator that I bought and used it for mock up,then stored it on the shelf for a while afterwards.Maybe a year and a half or so untill I was ready to use it.When I installed it, it wouldnt charge.I called a friend who owns a alternator shop and told him about it.He told me that I needed to "excite" the field and then it would be fine,I did as he suggested and its still working fine 6 years later.The problem is I cant remember exactly how I did it.I can remember the jumper wire and paperclip I used but thats about it It may be worth a try.As others have suggested I have to rev the engine to about 750 rpm before it will charge

Bill

[prpmmp]

If bringing the RPMs up does not work make sure the alternator is grounded real good. There is a ground lug on the back(run a wire from that to a good ground) remember sand all your ground spots and use star washers. Pete

[mrtexas]

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Originally Posted by Model A Bill

I had a new 1 wire alternator that I bought and used it for mock up,then stored it on the shelf for a while afterwards.Maybe a year and a half or so untill I was ready to use it.When I installed it, it wouldnt charge.I called a friend who owns a alternator shop and told him about it.He told me that I needed to "excite" the field and then it would be fine,I did as he suggested and its still working fine 6 years later.The problem is I cant remember exactly how I did it.I can remember the jumper wire and paperclip I used but thats about it It may be worth a try.As others have suggested I have to rev the engine to about 750 rpm before it will charge

Bill

I second this. If it has been sitting around a while the field coils lose their charge. I can't remember how I did it but there is always youtube...

[Talkwrench]

Should always go a 3 wire over those 1 wire jobs..

[prpmmp]

Originally Posted by Talkwrench

Should always go a 3 wire over those 1 wire jobs..

X2 Here is a link!!
http://www.madelectrical.com/catalog/alt-1.shtml

[Drbrown]

See attached. Agree 3 wire superior; always charging for me.

[4t8v8]

After trying many different alternator set ups, I finally settled for a mid '60's Chrysler 90A alternator with their dual input regulator. It reads the battery and field separately keeping the battery from ever overcharging. Stuck with it for the last 20 years. Works great.