Electrical / Gauge Cluster Issues

Chilipepper

Chilipepper

Member
Joined
Sep 16, 2020
Messages
32
Location
Florida
So I've been battling with a funky gauge cluster for a bit. In the past, cleaning the pins and bending them slightly to make a better contact worked. Now, they barely function. Before going around replacing parts I want to find out where the problem is coming from. I've been getting very personal with the all the wiring and here's where I'm at.

Suspicions:
- losing voltage from airbag control module to gauge cluster
- bad gauge cluster
- PCM not sending enough voltage

Known:
- resistance between cluster and ACM 0.5 Ohm measured at both CCD bus wires
- resistance between CCD bus (+) and (-) 120-121 Ohm
- resistance between ACM ground and chassis 0 Ohm
- resistance between cluster ground and chassis 0 Ohm
- voltage between cluster ground and chassis 0V
- voltage between ACM ground and chassis 0V
- voltage at CCD bus (+) and (-) each get 1-1.5V constantly changing which should be 2.5V

Questions:
- Do I have too much resistance in the wires from the cluster to the ACM, 0.5 Ohm, that could be causing the voltage drop?
- How would I measure the voltage being sent from the PCM to the cluster without unplugging the PCM with the battery in? Is it safe to do so?
- I know I'm losing voltage and I'm pretty sure my grounds are good. So where else should I check for that loss?
 
Check the ground on the block to the left of the oil filter and the other ground wires that are under the dash board on the drivers and passengers side along with the ground wires that are under the fastening screws for the lower dash speakers on the pass and drivers side.
 
CharlesHS said:
Check the ground on the block to the left of the oil filter and the other ground wires that are under the dash board on the drivers and passengers side along with the ground wires that are under the fastening screws for the lower dash speakers on the pass and drivers side.
Click to expand...
Ok I'll give them a shot. Do you happen to know how they're connected to the PCM to cluster circuit?
 
Am I supposed to be getting 2.5V at the CCD bus wires? I'm still getting an alternating range from 0.4-0.6 at both of them. I've checked for voltage from the gauge cluster all the way to the fuse box under the dash. The next thing would be the PCM. How would I check the grounds and voltage of the CCD bus wires at the PCM to make sure it's giving out the correct voltage?
 
Ok I think I confirmed my gauge cluster is bad. I began disconnecting each module connected to the CCD bus circuit and testing the voltage at the datalink connector. After disconnecting the ACM and cleaning the pins and plugging back in, I'm getting the proper voltage at the data link connector but the gauges still don't work so I'll be replacing the cluster.

What models/years have gauge clusters compatible with 98 TJ? I think I read somewhere that the XJ cluster from the same year has an oil pressure gauge not compatible.
 
Check the Mopar PN on the back of the cluster and confirm the years and models it was used.
The '97 had slightly different wiring than the '98 and' 99 and then things changed again in '00.
You should be able to use the gauge clusters from the XJs of the same years.
 
Chilipepper said:
Ok I think I confirmed my gauge cluster is bad. I began disconnecting each module connected to the CCD bus circuit and testing the voltage at the datalink connector. After disconnecting the ACM and cleaning the pins and plugging back in, I'm getting the proper voltage at the data link connector but the gauges still don't work so I'll be replacing the cluster.

What models/years have gauge clusters compatible with 98 TJ? I think I read somewhere that the XJ cluster from the same year has an oil pressure gauge not compatible.
Click to expand...
Hey Chilipepper, I know this is an older thread, but picking it back up again. I'm having a similar problem with my gauges, and after similar diagnostics to yours, I am also suspecting the cluster.

So did replacing yours fix the problem?
 
Mojave said:
Hey Chilipepper, I know this is an older thread, but picking it back up again. I'm having a similar problem with my gauges, and after similar diagnostics to yours, I am also suspecting the cluster.

So did replacing yours fix the problem?
Click to expand...
I ended up replacing my gauge cluster. I took it apart and noticed some burn marks on the circuit board. My only issue now is that I purchased a gauge cluster with 70k more miles than the old one read and have no idea how to roll it back, but it works perfectly.
 
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Chilipepper said:
I ended up replacing my gauge cluster. I took it apart and noticed some burn marks on the circuit board. My only issue now is that I purchased a gauge cluster with 70k more miles than the old one read and have no idea how to roll it back, but it works perfectly.
Click to expand...
There's another thread I swear I read 2 days ago where they had the thing "flashed" to correct the mileage. If I find it I'll link it here.
 
Chilipepper said:
I ended up replacing my gauge cluster. I took it apart and noticed some burn marks on the circuit board. My only issue now is that I purchased a gauge cluster with 70k more miles than the old one read and have no idea how to roll it back, but it works perfectly.
Click to expand...
Ok, thanks for the reply, good to know. Given what your experience was, I just purchased a new cluster, I guess we'll see if that fixes it. I'll have the same problem with the odometer but the reverse, the one I just bought has about 70k fewer miles than what I actually have on the jeep. Going to just take a picture of the true mileage readout before I switch the clusters, and put that in the jeep's records for full disclosure if need be.
 
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