alternator humming....???

so i did my v6-8 swap and i had to use my alternator from my original car and so i cut the wires spliced them together and i grounded it on one of the ground studs on the back of the alternator now in the car when i turn key on the battery light comes on on the dash which is normal..im pretty sure its charging cuz ive been starting and stopping it quite alot cuz i just got it started and im checking for fluids, timing it, driving it all that fun stuff. i turn off the engine and it sounds like a neon light like the kind ud hear in say a school or library that slight humm which is weird....any ideas some ppl said it was a bad ground...as a note i spliced the ground with the right size wire and soldered the connections. should i ground both poles on back of alternator?? its outa a 91 chevy caprice 350

hm... have to get back to ya on that one.....

If it's a used altenator , just pay the dough to get a new one and if it has two grounding posts , do it up.

hmm, my alternator i think did the same thing, it made a kind of whisteling sound. and went bad like 2 months later, id recomment getting a new one, only like 80 bucks or so.

this is my first post!!!!

so i found something that was a lil odd, while doing the swap i found that i needed to connect 2 wires together to turn my fuel pump on manually cuz the computer kept turning it off so i rigged it to a switch. now when i disconnect those wires the alternator stops humming now im completely lost on this haha anyone got any ideas.

got any details on how you wired the fuel pump switch, that's something i'd like to do with mine.

umm yeah i took computer totally off line proceeded to take out of car and burn in a huge pit, while i urinated on it and cursed at it then i found the main like power switchfor the fuel pump mine was a orange wire that i followed from the oil pressure sending unit all the way back to the relay (wiring digrams help) i spliced into that ran a long wire to my console, then found a 12 volt ingition which was to where my electric fan switch was spliced into that and ran a wire to my interior and plugged it into a switch u turn on switch while key is on and there u have it simple but effective security/safety feature

20 years of progress..... burned and pee'd on :(

i turn off the engine and it sounds like a neon light like the kind ud hear in say a school or library that slight humm which is weird......You have a wiring problem which is allowing voltageinto the regulator which causes the field coil and triacto oscillate. Trace the connector,(the 18 AWG brown wire is your suspect)to find the reason. The 18 AWG needs to have zero voltswhen your car is shut off. .§§§§§§§§§§§§§§§§§§§§§§§§§§§§§§REFUSE . . TO . . LOSE§§§§§§§§§§§§§§§§§§§§§§§§§§§§§§