Hey Gang, I put a gm 1 wire alternator on my current project ( 34 ford Pickup) with a 331 hemi. Ive wired literally 100 cars from scratch the same way. NOW I start my truck it shows 14.7 volts....turn ignition off & it keeps running & volts peg the gauge at 18. had to get out & yank the coil wire to kill it.....disconnect the alt. & everything works normal (except charging of course) New one wire alternator .
Do you have an electric fan? Also, depending on how you wired the exciter wire, you may need a diode in that circuit. I would really like to see some pics of the '34. Welcome to the HAMB. -Abone.
I've got to go along with Flamedabone, you have something else going on causing the feedback. Outside of the guys who are anal about not having any more wires show than absolutely necessary (main reason the 1 wire got into hot rod use after being used on farm equipment) the other reason is that you don't have to deal with the alternator feeding back to the ignition through the exciter wire. No diode in the line and no idiot light Next question Does your alternator actually only have one wire going to the battery or to a junction block to the battery and a black cap over the plug for the regulator or does your "1 wire" have an extra wire running to the ignition like this as we all the sudden have guys showing up thinking they installed a one wire alternator who don't actually have a one wire alternator. A one wire alternator looks like this with the black cap over the pins for the regulator If you indeed have the one wire like the above image you are getting feedback from the electric fan or from some other source.
Yep, as noted, motors are motors, whether they are using power or making power. A fan motor which uses...power (electrical), will turn into a generator (motor, power generator), if not wired correctly. How are your one wire alternator and fans wired ? Mike
Diode is the answer. Had a bad parking light socket that caused feedback to steering colmn, Diode ended the problem
A one wire alternator only has one wire to it period, that is the heavy wire to the Batt post on it. If it uses more than that wire it isn't a frigging one wire alternator.
We can only guess how everything is wired together. How about a schematic? or pictures, or something to go on. If the alternator is only connected to the battery, and the ignition switch is wired properly, it can't do that. Something is messed up, somewhere.
have 3wire gm alternater when wire as instructed wnwhen eng running battery is getting more than 15 v but if I disconnect the number 2 wire get 13.5-14.5 v ??
Feedback from something else you've got wired. Need to know more about the whole wiring system. Had a friend who had the same issue, and it was his electric fan feeding back. Had a toggle switch and if he powered the fan off first the engine died. If he didn't it kept running, and the voltage went nuts like yours. Put a diode in the fan circuit for him, and no more problems.
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