low voltage problem

[BKrause]

ok heres my problem..last summer my voltage gauge read 14 volts 24/7.. then one day it randomly started dropping.. now whenever my car is idle or stopped at a stopsign or if im not moving and put it in reverse or drive it goes down to 12 volts.. but if i give it the gas then it goes straight to 14 volts..

things to know: recently purchased new altenator, had it replaced 4 times because of squeaking pulley, none of the 4 fixed it.. had battery tested. even had a dealership look at my problem (i was doing an internship there, so it was free) they told me everything is normal but that blows my mind because just last summer it was running solid 14 24/7..

also iv never had any problems starting it or anything, i even put a new battery from autozone in just to test and same thing.. checked all my grounds, not completely but just took a look and everything looked good.. found a little corrosion on the positive cable.. cleaned it and actually removed the whole entire positive cable which hooks to the starter, alt, battery blahblah PITA..

im completely out of options.. i did tests with a fluke 88 and other voltage testers.. also when i turn my lights and ac and other things on it drops.. i mean u will see it go from 14 to 12 like nothin.. and with the fluke it was at 12.1..

im out of options..

[SlipStreamZ28]

Sounds like you put your alternator on backwards, when you hit the gas it's suckin power from the battery. Just flip it around and you'll be fine J/K

[Dudek]

what kinda of resistance do you have through your positive power cable?

[BKrause]

what kinda of resistance do you have through your positive power cable?

you know i didn't even bother checking that.. i don't have a voltmeter anymore though..

[1BADAIR]

do you have underdrive pulleys?

[MP81]

Regulator could be going in the alternator.

[Dudek]

im gonna doubt its his regulator since hes already replaced it 4 different times,
if you found corrosion in your power cable and "cleaned" it, im willing to beat thats your problem, just to much resistance.

[BKrause]

il try and get ahold of a fluke or any decent voltage meter and see what the resistance is and post back.. thanks for the help!

[prorac1]

I agree with Larry, do you have underdrive pulleys? My car did that with underdrive pulleys. Does it hold at 12 volts when it draws down, or does it keep sinking? I would let it sit with the lights and blower motor on (blower motors draw a LOT) and watch what it does. If it will hold a constant 12 volts I wouldnt worry about it. Eric L

[1BADAIR]

i kinda have this issue with mine. mine isnt really low enough to cause issue but lower than i want. it used to be up around 13.8 and now it s like 13.1-3
cold mine is fine but when drops when hot. i still have the factory alt. I was gonna try a new one when i can afford it even though it load tests fine

[prorac1]

I had the issue with this motor (my LT1) in my Green 94 Z28, but when I put it into my Red 97 SS (Same alt, pulleys, and all) the issue went away. I have perfect voltage now, so im guessing it was a wiring, or ground problem with my 94. Like Larry said it was OK, but lower than I liked. It was kinda cool, lol, the lights would dim slightly at idle, lol. Eric L

[BKrause]

it doesn't drop below 12 from what iv noticed just sits right there at it.. and yeah i had everything the same and it never did this before.. it has got to be wiring..