Gauges don't work

Dfrost89

Dfrost89

Member
Joined
Mar 28, 2020
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31
Location
Kirksville Missouri
Hey everyone, I’ve got an early model tj. It was produced 3/96 but considered a 97. My gauges do not work. They will All work doing the test with the gauges. It’s the bus wires I believe. I have a heads up display that works from my obd2 so I know the pcm is good and reading the Jeep runs fine. Also the back lights in the cluster doesn’t work. My dome and floor lights still work. Wondering if my light switch could be bad. The turn signals still flash in the cluster also, so I believe it has sometime to do with only the bus wires. Please help, would love to ditch the heads up display and have my gauges back. I have not tested the bus for the 2.5 with a multimeter yet. I do not know how to operate one.
 
The first place I would start is inspecting the wiring in that case. The fact that the gauges work in test mode (when you turn the key) means that the cluster itself must be working. I suspect the issue is wiring related, so you should start by removing the gauge cluster and very thoroughly inspecting the wires, as well as the wires under the hood too.

It's not going to be fun, and it's going to take a lot of time and patience, but if I had to guess, that's likely where the issue is.

Look for any aftermarket wiring modifications / accessories that could be causing this as well.
 
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Remove your instrument cluster and take a picture of the back of the cluster and the wiring harness that plugs into it.
 
Chris said:
The first place I would start is inspecting the wiring in that case. The fact that the gauges work in test mode (when you turn the key) means that the cluster itself must be working. I suspect the issue is wiring related, so you should start by removing the gauge cluster and very thoroughly inspecting the wires, as well as the wires under the hood too.

It's not going to be fun, and it's going to take a lot of time and patience, but if I had to guess, that's likely where the issue is.

Look for any aftermarket wiring modifications / accessories that could be causing this as well.
Click to expand...
All the modules have to be plugged in for the circuit on the bus to work right? The picture I attached says HVAC controls for 96 1/2 only. I believe that’s mine. I have 2 wire plug in with the stereo wiring that isn’t plugged to anything and wonder if it needs to be to complete it.

B0EB6452-F4F7-478A-B25B-C3A3432314B8.png
 
Daryl said:
Remove your instrument cluster and take a picture of the back of the cluster and the wiring harness that plugs into it.
Click to expand...
I will
Daryl said:
Remove your instrument cluster and take a picture of the back of the cluster and the wiring harness that plugs into it.
Click to expand...
The wiring seems to be in good shape. I peeled the tape back so I could inspect it. I’m 99% it’s the bus wires but I don’t understand wiring and how it all works much. So Idk how where the signal all runs through. The obd2 is reading but it comes directly from pcm or computer right? What is the route of the other bus wires?

AD613746-68F7-483C-960D-11A4E6F1DAF8.jpeg


996EB036-8007-41EB-9B27-DE995C2C515B.jpeg


97DFF080-D168-4E92-87F4-ADB1DBC6D5B7.jpeg
 
Here is that plug that I’m not sure what it is, it’s in the stereo wiring loom. Every video I’ve watched on tj stereos did not have this plug. Idk what it is.

85226071-F9BB-4105-93F7-D983F7AF0F96.jpeg
 
Dfrost89 said:
Could that be the problem?
Click to expand...
No, just noticed they were missing. The brown sockets are for dash illumination. The gray sockets are for the warning lights. Read the back of the missing lights and if you have that option there should be a bulb there. Remove the the sockets one at a time and check each bulb with some jumper wires and your car battery. Replace any bad ones. Then plug the two instrument cluster harnesses back in and start the Jeep. Wiggle the wiring harness while watching the instrument cluster for intermittent gauges or lights.
 
Daryl said:
No, just noticed they were missing. The brown sockets are for dash illumination. The gray sockets are for the warning lights. Read the back of the missing lights and if you have that option there should be a bulb there. Remove the the sockets one at a time and check each bulb with some jumper wires and your car battery. Replace any bad ones. Then plug the two instrument cluster harnesses back in and start the Jeep. Wiggle the wiring harness while watching the instrument cluster for intermittent gauges or lights.
Click to expand...
I have tried wiggling it and nothing happens. Could the light switch be causing the cluster back lights not to work?
 
Dfrost89 said:
Hey everyone, I’ve got an early model tj. It was produced 3/96 but considered a 97. My gauges do not work. They will All work doing the test with the gauges. It’s the bus wires I believe. I have a heads up display that works from my obd2 so I know the pcm is good and reading the Jeep runs fine. Also the back lights in the cluster doesn’t work. My dome and floor lights still work. Wondering if my light switch could be bad. The turn signals still flash in the cluster also, so I believe it has sometime to do with only the bus wires. Please help, would love to ditch the heads up display and have my gauges back. I have not tested the bus for the 2.5 with a multimeter yet. I do not know how to operate one.
Click to expand...
Do your park lights and tail lights work ?

My gauges all worked and my multifunction switch was fine but I had a shorted, broken connector which affected the park, tail and dash lights. All the fuses were fine.

DSCN2263.jpg


Thankfully the plug is still available thru Chrysler.
 
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billiebob said:
Do your park lights and tail lights work ?

My gauges all worked and my multifunction switch was fine but I had a shorted, broken connector which affected the park, tail and dash lights. All the fuses were fine.

View attachment 148930

Thankfully the plug is still available thru Chrysler.
Click to expand...
Yes head lights, tail lights, parking lamps and turn signals all work and done lamp and floor lamps but not the cluster lights or the lights behind HVAC controls
 
There was recently another forum member with a similar problem.
Since the dome and courtesy floor lights work, but the instrument cluster back lighting is not working; it would be a good idea to verify the dimmer function in the head light switch is still working.
You could remove the headlight switch and with no electrical harness's connected spray some contact cleaner inside the switch and cycle the switch functions to see if there are dirty contacts inside.
 
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