Hello. I own a 1991 Jeep Cherokee XJ (4.0 liter and inline 6, 5-speed standard transmission). A few months ago my engine essentially exploded and left a small hole in my engine somewhere (story for another time). Afterwards my coolant basically fell out all the time and since I am at college I didn't drive the car anymore and its been sitting outside my apartment since about November. After I came back to campus (January) I decided to turn on the car and drive it around the block to get the fluids rolling. About halfway into my adventure the car died for seemingly no reason and wouldn't turn on for about a minute or two and then it started up again and I returned home. Afterwards I spent each night turning on the car and letting it run as long as it could before overheating, however now none of the gauges work. No fuel, speedometer, temp, oil, battery, nor RPM. All of these were set at zero. I decided to pull out the cluster and check the back for any possible issues but found nothing. Now I'm very skilled with electronics and I have access to a multitude of electrical components so I was hoping I would just have to fix up a few ruined soldering areas however that wasn't the case. I have a feeling it could be because of the ECU, which was replaced sometime ago by my father from a junk jeep. I have only replaced the spark plugs and wires on the car.

TLR, gauges don't work, i think its the ECU because car keeps dying if i drive it, where the heck do I find my ecu in the vehicle???

 

Ensure that the grounds are good. Check the ground in the dash area to the negative terminal for Ohms. Check the Ohms across the ground strap for Ohms from the bolt on the block to the firewall.