i was hoping someone could possibly help me here. i drive a 1987 Z28 with a crate ZZ4 350. the kid i purchased the car from was a far cry from the ASE certified technician he claimed to be. that being said, my charging system is not charging at idle. the volt meter drops to about 7 volts, lights go dim, and my radio turns on and off. i replaced the alternator figuring that was the problem, however it was still there. as i had a warranty on the alternator, i replaced it again, still no charge at idle. as soon as the revs go higher than 850 she charges at 14.4 volts. the alternator on it now is the older style 3-wire that i believe came on 1982 chevy 350's. anybody got any ideas as to what i might do?

 

It might be your voltage regulator. Were underdrive pullies installed?

 

If that alternator is as old as you think it is, just replace it. Buy at a min. a 105amp one. With those signs better to replace it then being stranded on the side of the road. [sm=chairshot.gif]

 

I dont think it could be the regulator since he is on his third alt and still having the same problem. But I do agreeon the question of underdrive pullies.

 

if you don't have a problem with your belt. the problem could possibly be a ground issue. i would try running a new ground from the engine to the body then make sure the battery ground is snugly secured to the engine as well as the body. cleaning all the wire connections including the starter might also be something to look at. Sick

 

thanx for the replies. and here are my answers....1. No underdrive pulleys were used in the making of this 350. 2. I replaced both the ground AND the positive cables and installed a separate ground from the battery to body and engine to body and battery to engine,(aren't dual post batteries great!).
so my question would be, if the alternator is a 60 amp, would going to a 105 amp help at idle? if i am correct, doesn't the alternator go full field when first started to recharge the battery after sitting? why wouldn't it do this if the regulator noticed such a drop in voltage. and last but not least, do they make a 105 amp alternator as a drop in unit without changing brackets?
all replies are greatly appreciated.

 

My opinion is a 60 amp alternator is too small for the power requirements of ZZ4 350. 105 amp one is standed on stock 350's from the factory and a DELCO alternator should be no problem.

 

thanx for the reply. the one thing i forgot to mention is that the pulley sytem is from a 1982 setup, another words, v-belt pulleys. the body and interior is 1987, the block is 2004, the intake is 1980, and the front accessories as far as i can tell are 1982. so in lies my question, can i get a 105 amp alternator for a 1982 v-belt setup?

 

Yes....

 

blackz87....thank you for your help. this has been driving me nuts for quite sometime now and it seems every one i talk to is a figgin idiot! where would be my best source and or part number if anyone knew it to get this alt?