My cars been acting weird lately: stereo cutting out, windshield wipers blowing fuses, CEL coming and going for no reason, oil gauge wandering into the negative PSI range, taillights acting like their at a techno raver party (well, not yet). Is my cars brain paranoid schizophrenic and needs to be replaced? Or could it just be the alternator giving out fuzzy voltage? I read 12.5V cold and 14ish while running.

 

Obviously I can wield a multimeter without hurting myself, but where would I start to investigate the gremlins that plague my car?

Souns like you have lost a diode in your alt, that's the first thing i would check. Oh, and battery connections too, maybe check engine and chasis grounds. My moneys on the alt.

Yup, classic signs your alternator is toast. Pull it and take it to shucks ect, and have them test it.

All the symptoms you describe are either in the dash or behind you. This tells me that your problem is likely to be under the dash, probably in the wad of wiring behind the fues panel. The connectors get brittle with age and sometimes the wires IN those connectors start getting loose from the vibration in the car. When that happens all KINDS of weird stuff starts happening. WOuldn't bet against a dead/dieing alternator, but double check your wiring under the dash. Start with the platic connectors behind the fuse panel.

I'd start with the alternator. Sounds like the voltage regulator is pushing too much power out into your electrical system. Is your voltes guage riding above 16amps ?