I have a test for ya guys/gals. Lets see if any can diagnose the problem...

I met up with Mrs Howler for our usual Fri afternoon coffee (We get out of work at the same time on Fri)

She tells me the CEL is on.
I ask if its "running" okay.
Its running okay but it is quite HOT (over 210*) And she says the BATT gauge is reading low.

I get in and start it up. Starts fine. 3 sec. later CEL comes on. And BATT gauge starts to drop.
But its running smoothly.

XJ INFO: 1991 Laredo 4.0L AUTO 169,000mi.

Upon getting home, I pull the codes.

1st- CODE 12: Battery disconnected.
2nd- CODE 22: Coolant Sensor circuit low voltage.
3rd- CODE 41: ALT field circuit.

Took BATT and ALT out and had them tested. BOTH passed.

I fixed the problem.
Lets see if someone can diagnose what was wrong.

Any guesses?

 

Bad or corroded ground wire to the block.

 

It's a jeep?

 

Ouch!
You aint gonna last long round here.

 

definitely sounds like a ground problem probably a strap or a main ground from battery to block

 

BAD or CORRODED GROUND:

X

All ground wires were replaced along with BOTH BATT cables.

ITS A JEEP?:

As a QUESTION, the answer is YES.
As an ANSWER, the reply is: Not an excuse