jmrec100

Absolutely right. My 1994 . I had a bad ground. The internal PCM was trying to regulate on, off, on, off
Finally commited suicide and fried itself. Almost caught fire. Lucky thing, the PCM fried. Wiring was ok. I regularly check my battery cables. I'm going to replace them with those suggested. Thanks.
Check your ground, check your ground. My new mantra whenever I drive.
Really can install an external voltage regulator? How. When did Jeep/Chrysler switch to external Voltage regulator.

rmcrom

Does the volt gauge still work if you run an external voltage regulator?

Jimbo Slice

I think they frown on folks linking other forums, so just google "Jeep XJ external voltage regulator".

There's a few how to's complete with part numbers and alternatives for the external regulator project.

tinytrax78

http://www.backyardmechanic.org/how-...jeep-chrysler/

jmrec100

Thanks.

rmcrom

Another tidbit, I get 13.6v running at idle with everything off except the radio. I get 12.6v with high beams on, a set of hella 500 on, AC blowing on max.

rmcrom

I wired in an external voltage regulator and I get a nice 14v while driving. However, instead of a voltage spike over ~3000 rpm, now I get a blown fuse on the +12v source wire feeding the voltage regulator. So stock voltage regulator = voltage spike, external voltage regulator = blown fuse. Would it be reasonable to think it's the alternator at this point?

rmcrom

Replaced the alternator and that seems to have fixed it. I switched back to the original voltage regulator.