BestTeeth

Whenever I start my Jeep up, the temperature gauge instantly goes to a particular reading and never budges from there, even on a very cold start, temp sensor has been ruled out because unplugging the sensor and starting the XJ makes the gauge hit the same temp reading on the cluster. just below mid way on the temp reading on my 2000's XJ

I did a bus test on the gauge cluster, and all the gauge dials are moving as expected except for the coolant temperature gauge, that one is stuck in the position it's been stuck in since I got this XJ, it's definitely not the sensor because I tried testing it when it's unplugged and it still gave the same reading, nothing looks burnt on the back of the cluster or anything after taking it apart, any suggestions for what might fix that issue? For reference, nothing on the back of the cluster looks bad, all the contacts and caps look perfectly fine, I'm unsure what else to look at here since I sincerely doubt it's the actual gauge cluster itself. I am however open to insight from all you potentially more knowledgeable folk

BestTeeth

As a bump to this, I've used contact cleaner on every contact in the cluster just in case, as well as the plug that goes into it, plugged it back in, ran the bus test, it's still going directly to the same reading the moment the gauge gets power. Any insight would be greatly appreciated.

Jim Malcolm

If the Bus Test didn't cause it to move, then the gauge is bad... The ECM is providing the temperature via CAN. If the gauge isn't displaying it correctly, then there's an issue with the gauge/cluster.

BestTeeth

An update to this while I was waiting for replies (Thank you Jim,) I took the whole cluster apart, used some contact cleaner on the contacts behind the cluster itself, brushed some of the crust off, slightly bent the pins in the cluster like this video did:
I've since put it back together enough and plugged it in, and it worked, I'm now properly getting a reading on the temperature gauge, we'll see if this fix is permanent or temporary. I hope this helps someone else!