98 4.0 Gauges Not Working

Chilipepper

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Joined
Sep 16, 2020
Messages
32
Location
Florida
I recently got done replacing the thermostat and I had the thermostat sensor unplugged without unplugging the negative terminal of the battery. Prior to this job the gauges were all working. The TJ starts fine and everything works, including the cluster lights, except the gauges. As of now, I have checked the ground under the driver side speaker, the ground behind the gauge cluster, and some grounds in the engine bay. I've pulled the cluster and cleaned the pins. I've checked all of my fuses behind the glovebox and in the engine bay. All I've been able to find is that I'm not getting any voltage where fuse 12(panel lamps) behind the glovebox goes. It's not the fuse because I've replaced it. My multimeter reads 0V when putting it into the fuse box. There's two orange and one tan wire coming out of it. I traced it to the right plug that goes into the gauge cluster and I don't seem to be getting any voltage at that plug either. I'm loosing voltage somewhere and I'm having trouble locating it. Could this have anything to do with the thermostat sensor being unplugged?
 
I seriously doubt pulling the temperature sender with the battery connected had anything to do with it.

Try this... with the engine running and the gauges not working, take the palm of your hand and give the top of the instrument cluster bezel a good firm slap or a good sound pound or two with the side of your fist and see if the gauges come back to life. If they do I have the probable fix for you. Early TJs had that problem... a lot.
 
The 10A fuse #17 from the PDC and the 10A fuse #10 from the fuse block behind the glove compartment both send power to the gauge cluster. I would check both of those fuses. Terminal 9 on the ignition switch powers up the fuse block behind the glove compartment.

More electrical information can be researched in the PDF of the FSM which is in the TJ Resources section.
You can look in the electrical section of 8W 10-10.

https://wranglertjforum.com/threads...ice-manuals-fsm-technical-documentation.4618/
 
My '98 did this once upon a time. I pulled the cluster and bent the pins slightly so they would make better contact and no issues since.

The problem was microscopic black oxidation marks on the pins and clips. I tried your solution along with cleaning the pins/clips with contact cleaner and scotch bright several times; the problem returned each time. There was a TSB addressing that problem in both TJs and XJs. I had the TSB performed which cut out the old buss connectors and solder in new ones; the problem returned. Never did fix mine in the 20+ years I owned my XJ.
 
I seriously doubt pulling the temperature sender with the battery connected had anything to do with it.

Try this... with the engine running and the gauges not working, take the palm of your hand and give the top of the instrument cluster bezel a good firm slap or a good sound pound or two with the side of your fist and see if the gauges come back to life. If they do I have the probable fix for you. Early TJs had that problem... a lot.
I tried that too. I even took the plugs off of that metal piece they clip onto and physically put each one into the cluster firmly and nothing. I'm going to try what @Skylinessuck said and hopefully it'll fix it. Are there any important grounds other than the one under the speaker that I should check?
 
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The 10A fuse #17 from the PDC and the 10A fuse #10 from the fuse block behind the glove compartment both send power to the gauge cluster. I would check both of those fuses. Terminal 9 on the ignition switch powers up the fuse block behind the glove compartment.

More electrical information can be researched in the PDF of the FSM which is in the TJ Resources section.
You can look in the electrical section of 8W 10-10.

https://wranglertjforum.com/threads...ice-manuals-fsm-technical-documentation.4618/
My fuses were good. Checked them with the engine running and pulled them to check their resistance too. I guess I'll take a look at the fuse box grounds.
 
UPDATE: Fixed...for now?

I had cleaned the pins and bent then and nothing. I bent them a little more and cleaned with isopropyl alcohol this time then some of the gauges came to life but they were very delayed and unstable. I drove around for about 20 minutes and by the end everything was working again.
 
Sounds like the typical issue. I'd clean then again, bend the pins slightly, and give them a lite coating of dielectric grease. Lots of write ups on the interwebs about it.