I've just gotten a new alternator this month, yet I'm still having issues with the car dying. Sometimes its right after startup, sometimes its after I've been driving awhile. What usually happens is the voltage just drops right to the bottom, the symptiom of a bad alternator. Now, I've had the voltage regulator checked and its okay, and the alternator is a rebuilt one. My mechanic has checked all the areas that could be drawing heavy current for the alternator to keep killing itself and has found nothing unusual. Within the last few months I've also eliminated just about every rough running cause there could be. The only thing I've noticed is that its very hot (90+ F) and I get a flash of the oil light on startup (though I use 15w40 in this weather) and I've topped up my oil too. Any ideas on what could still be causing such a drop in voltage?

 

I went through 2 "rebuilt" alts. before I got a good one. Do you have a multimeter? Use it to check battery voltage with eng. off and then with eng. on. should be at least 12 for the former and at least 13.5 for the latter. If you don't get the latter it is probably a bad alt. Is it a paris rhone?

 

Flint,

Even if the alternator was bad, the engine would still run off the battery. Try checking for a bad connection starting at the ignition switch.

Dennis

 

And check the ground strap from the engine to the frame on the pass side. A poor cable or connection will drive an alternator crazy. The factory piece is a raw stranded copper cable. You can by a new generic strap, or get an insulated 1ga cable replacement, I suspect.

 

Don't forget the possibility of a bad ignition switch.