voltage spikes

[murdawg25]

I have a 99 neon r/t that is having voltage spikes at random moments it will go from 13.3V ish to up to 19V. I was told it was the alternator so i replaced that but the spikes are still there. HELP

[RadarLove]

Is this on an aftermarket voltmeter? I'd triple check those connections first. The voltage regulator for the alternator is part of the PCM circuitry. Might try finding a cheap PCM and swap it out.

Grounds/shorts can cause voltage spikes and typically cause a code 22. The most common location by far is the downstream O2 sensor rubbing on the axle. But there are dozens of locations you'd have to check...

Best of luck!