powereverything

My 1984 928S is freaking out on me. I've had three alternators installed but I continue to get weird, intermittent low voltage readings, usually ending in the car not being able to start. Today, It started and after driving 30 miles everything was great at 13 volts or so. As soon as I stopped the car, and tried to start it, it wouldn't get over 11 volts. The gauge is having highly sensitive reactions to turning on the defroster, the headlights, turn signal etc -- almost like a punch in the gut. The alternator's not holding a charge, but it's not the alternator.

Any ideas?

deliriousga

This was not in my 928, but may help with diagnostics. I had a freaky problem where the guage would peg the top of the meter. I would shut down the car to try and prevent damage, but then it clicked like the battery was dead. I had the battery tested and it checked out as ok. Thought it must be the alternator, so I replaced it. Same thing still happened. Next I changed the battery cables out, but still the same. Next was the starter (thought maybe that was causing the clicking if the solenoid was going out), but still the same. After a couple of months of frustration and a few hundred bucks it turned out to be.....the battery that tested good. Turned out there was a short in the battery so sometimes it would accept the charge and sometimes it wouldn't. Just happened to accept the charge when they tested it. After replacing the battery, no problems at all.

Also had a problem similar to yours with another car where the alternator light would come on (has no charge) and the car would give me alot of trouble. Cleaned the terminals down to shiny metal and the connections and all problems went away.

Check all your contacts if you haven't already for corrosion and road grime. There's a great annual check-up/cleaning on http://www.nichols.nu/tip725.htm if you haven't done it yet.

Hope all goes well!