1997 XJ auto 4x4. I was doing some probing and testing of circuits in the PDC under the hood trying to find a switched source to trigger a relay for when the Jeep was on only. I got to the relay for the factory cooling fan and found one terminal only gave power when the Jeep was on. I put a test lead in it to see if it would power the relay I was trying to hook up and the lead wire accidentally grounded. The wire in the factory harness is a blue wire with a white stripe.

Now there is no communication to the computer to see if there is a code. The CEL came on but when I turned the key to off and then back on the CEL did not come back on. The terminal I was testing originally gave me 11.9ish volts on my voltmeter. Now it only gives me 2.3ish volts. The Jeep will turn over but not fire. None of the gauges seem to respond now either. The battery has over 12 volts but the gauge does not register a reading. The only gauge that moves is the oil pressure but only a slight bit and not even enough to get to the first notch. All the dash lights light up as normal when the key is turned to the ON position.

I replaced the computer with a used one from another 97 and nothing changed. I now put in a brand new computer and still NOTHING changed.

I am at a total loss as to what to try next. Any and all suggestions will be entertained!

 

Hi is your jeep immobiliser connected.

 

Did you check the big fuses in the PDC under the hood?