Alternator Mischief

[hanleyclifford]

Just when I thought I had made a near trouble free passage I discover 9 volts at the stator terminal engine not running. Am I correct in suspecting one or more output diodes are leaking and/or shorted?

[Mo]

Hi Hanley,

Large red to the Battery and a wire from the ignition to solenoid right. The red one should read 12 V and the small one from ignition should read 12 V with starter button pushed or key in crank position. If this is not so look for bad connection.

Otherwise, need to check the output of the alternator and see if it's charging. Hanley, I hope that helps as electrical is not my forté.

[hanleyclifford]

Mo - Thanks for the reply. Problem is I have external regulation and even with the regulator harness unplugged, that is - no connection to field, no battery sense but only the output cable on the alternator I still get voltage at the stator! What else can it be? Somehow voltage is getting from the output terminal to the stator even when the engine is not running. I caught the problem when I saw the stator indicator light on the regulator glowing slightly and felt warmth on the alternator casing. I ran the engine and the alternator still puts out full values but upon shutdown the problem returned. I had to disconnect the cable from alternator output terminal. Does anybody remember a thread about this several months ago?

[ndutton]

Are you getting heat with the output attached but the regulator disconnected? I'm far more concerned with the heat than the voltage reading at this early stage. They may be related but maybe not. Let's find where the heat is coming from.

[hanleyclifford]

Yes, I am getting heat with all wires detached except the alternator output cable.

[ndutton]

In that case I think your original thought of compromised diodes in the rectifier bridge is likely. Time to start looking for an alternator shop? If it were me I'd take the regulator along too so they have the full picture.

Good thing you found it now, at the start of a planned respite.

[hanleyclifford]

Thanks, Neil - In fact the shop where I bought the regulator is nearby and I will take both units to them.

[lat 64]

Your regulator is what biologists call anadromous. It is going to it's birthplace, it's going home to die and spawn a new generation. (get it? generation) Ha! I kill me!

Sorry, too much left over egg nog here.

Cheers Hanley,
Russ

[jhwelch]

Not sure if it is still there but just down the street on Rt. 1 northbound in Titusville is a tiny alternator shop (not sure about the dog, though). When my alternator went out some years ago the man fixed it for free; a wire inside needed to be reattached.