1998 TJ, Good Battery, No Power

[mrhiggs]

Driving, check gage light on, pegged at 19 amps, turn off, won't start, no power, no lights, nothing.

Battery good, terminals connected, not corroded, no blown fuses.

Found a post with similar issue they swapped some fuses and it fixed it. Tried it and it worked (got power back) but lost power again when I went to crank it over. Also found that if I disconnect the negative terminal on the battery same thing happens, get power back but lose it when I go to crank it over.

Where's the short?

Thanks

 

[ItchyDong]

The short would imply that a fuse blew. Not that disconnecting cables suddenly brings it back to life momentarily.

 

[macleanflood]

What happens if you disconnect the alternator cable...you could disconnect it from the PDC rather than the back of the alternator.

Any visible damage to your PCM?

-Mac

 

[KennethS]

Driving, check gage light on, pegged at 19 amps,

I am guessing that was 19 Volts as the factory has a Voltmeterr and not an ammeter.

I doubt there is a short as that should not cause an over-voltage event.

 

[mrhiggs]

The short would imply that a fuse blew. Not that disconnecting cables suddenly brings it back to life momentarily.

A short is any interruption in an electrical circuit, which is clearly happening because I have no power, in this case it isn't blowing the fuse.

 

[mrhiggs]

I am guessing that was 19 Volts as the factory has a Voltmeterr and not an ammeter.

I doubt there is a short as that should not cause an over-voltage event.

My bad, 19 volts, I don't think it was a true over-voltage event. I think the short fed a false reading to the voltmeter.

 

[mrhiggs]

What happens if you disconnect the alternator cable...you could disconnect it from the PDC rather than the back of the alternator.

Any visible damage to your PCM?

-Mac

12 volts at the alternator, PCM looks good.

 

[mrhiggs]

Disconnected, blew out some dust (no visible corrosion), started right up.

not my Jeep

 

[macleanflood]

Not 100 percent what you did but fixed is fixed.

Newer TJs have bad PCMs and crappy wiring harnesses.

-Mac

 

[ItchyDong]

A short is any interruption in an electrical circuit, which is clearly happening because I have no power, in this case it isn't blowing the fuse.

*Large Sigh*

Whatever you say, bud. Good luck.