I just dropped in a 350 into my 86 transam. I've been driving for a couple weeks and the voltage ouput was good. The guage read a little over 13.....
Now starting this week it would be under 13 and when i drive at nights with my headlights on, the guage is showing 10.5-11.5....

So today, i put in a new alternator, the 102 amp one. and it has the same problem. is something else going out in the car. i disconnected my stereo to see if that was at fault but it wasn't.

also, my idle is started to jump around too.. Is something draining the hell out of my car.?

I checked the voltage at the battery with a voltmeter and it said 14.6 V....? But the guage in the car is 11.5 about...

What could be the problem....thanks for the help.

 

May sound simple but check all ground wires. My main ground to the block was loose and all ground was flowing thru that small wire leading to the fender! I found out when I grabbed the wire and got a handful of hot, melted plastic, ouch! I had just installed my L98 and coudn't get it to run, drove me nuts for weeks!

------------------
Rob P
89RSconvtZZ4TPI
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

Have you noticed your lights dimming? If your voltage is dropping that much with the car running, the lights should dim on the car.

I had the same problem when I installed the 350 in my car. The idle came from having a cam that had too much lobe in it. With a new motor, you have to change chips, unless you are putting in a direct replacement.

If you haven't had any problems starting the car, it may not be a big deal. The charging problem that I had was from a bad alternator, this caused my battery to go bad. I ended up just throwing on a second ground strap, and that took care of a lot of the problem...

My idle still bounces though...

-=-Mike

------------------
1989 RS.. Newly installed 350,bored out 30 over, Hypereutectic pistons, double roller cam, double roller timing chain, accel wires, blue streak cap and rotor, platinum plugs, chevy caprice 350 chip.

 

I had a custom chip made for the car...so my idle was perfect until a couple days ago...

And now the car is surging just a little on freeway cruise. no check engine light or anything...

I bought a new battery for the car today too, but that didn't fix that problem...

Where did you put the other grounding strap?

thanks

 

well this may be nothing to help you..but it was my problem.....when i relaced my alt. i put the power wire on backwards, and the connector was shorting itself out on the alt. case and draining the battery and eventually killing the alt........maybe this helps...peace

------------------
1990 Firebird
(400+HP 350 still in progress)
Complete custom interior
License Tag `URLOSIN`