ksr

Last Monday, my car needed to be jumped. It had been fine before that. I started it, took it out for a ride hoping to recharge the battery. The dash lights flickered a bit the whole time. I turned the a/c on and then the car lost all power, everything. I got a jump and got it back home.

I figured it was the alternator. Installed a brand new one. Jumped the car. Same flickering in the dash lights and other interior lights. Erratic readings from the charge indicator on the digital dash, which would also climb into the red/danger zone if I revved it up over 2,000 RPM. I was going to take to a nearby garage, and as I put my foot on the brake and was about to put it in gear, the car died.

Any theories? Bad cell in the battey? It's only two years old. I read that sometimes vaccuum issues with the brake lines can cause a loss of power, but the flickering happens before you hit the brakes.

One odd thing I noticed is that when I used my jump starter, no voltage appeared on the readout when I hooked it to the positive battery terminal and the chassis. I only got a readout when I hooked both cables from the jump starter to the battery terminals. That sounds like a possible grounding issue to me. The ground connection from the battery to the chassis looks clean and is tight..

Tootie Pang

iTrader: (2)

Either its a bad alternator cable/connection or a bad ground cable/connection to the chassis. My alternator cable melted since it was too small for the stock but healthy 105 amp alternator I had in there. Once I replaced it, I realized I had had a low voltage problem, due to the poor cable/connection, for a long time.

ksr

Thanks. I'm going to check over the connections. They looked clean when I replaced the alternator, and I was sure to tightly attach the cable to the alternator. The chassis ground wire is tight and clean too.

Tootie Pang

iTrader: (2)

There's two important grounds - the ground strap from the engine to the chassis at the firewall and the negative battery cable which I ran directly to the engine block. I also have numerous ground wires from the battery negative post to the chassis at the fender.

The alternator wire was really small. 8 gauge at most which I don't think supports 100 amps. Not sure how Chevy figured this size. When I put in my 200 amp alternator I also replaced this cable with a 2 gauge. It was amazing how much of an all around improvement it made to the whole car- lights, engine, sound system, everything.

ksr

Turns out it was a bad battery. Pulled the positive cable off and a bunch of acid spilled out.

I rashly replaced the alternator because it was 32 years and I've never had a battery fail so quickly. The Interstate was less than two years old. Pretty pathetic. So now I've got a 32-year old spare alternator if the new one ever dies.