I just got everything back together for a first startup. When the ignition is on my alternator hums. But only when the wiring connector is pressed inward. It started doing this and jiggling with the connector got it to quit doing it all the time.

I'm getting 12.55 volts at the battery, 12.50 after the kill switch, 12.49 to my distro block in the bay, and 12.49 to my alt. What could be going on here...nothing?

 

what was the last thing you did concerning the alternator?

 

I don't think I follow...(its early!)

Installed it?

 

no what did you do? Is it new or somthing? Or did it just start doing this out of the blue? take it to autozone for free and they will test it for you.

 

This alt is not new. Not old but not new. A friend has a busniess that rebuilds alts and starters and he built this one to 140 amps. It has never done this before.

 

Looking at your voltage readings, it sounds like you have dailed diodes this will also cause a high pitch noise from the alt.

 

I couldn't get the voltage when the car ran for the extremely short time it did. But the voltage was fine with everything connected.