kcox506
Well-Known Member
- Joined
- Oct 14, 2013
- Location
- Hayesville, North Carolina
I have a 1994 ZJ Grand Cherokee 4.0. The temp gauge will not read a temp.
I have done the following trying to diagnose the issue:
- Changed Temp Sending Unit (single wire sensor back of head, not the coolant temp sensor for PCM)
- Connected sensor plug directly to battery negative. That should max out temp gauge. No change.
- Checked Continuity from Sensor plug to back of Dash Cluster Plug. All good.
- Checked pins on all wires to ensure nothing is moving back when plugged in.
- Checked back of dash cluster for ground and 12v to gauge itself. Checked out.
- Changed the Oil/Temp sensor section in the cluster with a donor. Still no temp.
- Tried the whole donor cluster itself. Still no temp.
What could I be missing? Another bad temp gauge?
I even went as far as testing out a YJ 1994 Temp Gauge and swapped that in my cluster. Fits but the resistance appears to be different, so it just maxed itself out immediately. I am not sure if that helps but its something. I've done extensive searching online, but all I can find is people misidentifying the coolant temp sensor with the temp sending unit.
I know I can run my own gauge but that's for the birds. I want my stock gauge to do stock gauge things. Send help.
I have done the following trying to diagnose the issue:
- Changed Temp Sending Unit (single wire sensor back of head, not the coolant temp sensor for PCM)
- Connected sensor plug directly to battery negative. That should max out temp gauge. No change.
- Checked Continuity from Sensor plug to back of Dash Cluster Plug. All good.
- Checked pins on all wires to ensure nothing is moving back when plugged in.
- Checked back of dash cluster for ground and 12v to gauge itself. Checked out.
- Changed the Oil/Temp sensor section in the cluster with a donor. Still no temp.
- Tried the whole donor cluster itself. Still no temp.
What could I be missing? Another bad temp gauge?
I even went as far as testing out a YJ 1994 Temp Gauge and swapped that in my cluster. Fits but the resistance appears to be different, so it just maxed itself out immediately. I am not sure if that helps but its something. I've done extensive searching online, but all I can find is people misidentifying the coolant temp sensor with the temp sending unit.
I know I can run my own gauge but that's for the birds. I want my stock gauge to do stock gauge things. Send help.
Now that's back together and the gauge works. So I created my own issue and spent unnecessary time and money trying to fix it. I am a little baffled I didn't figure that out sooner, but I was probing something else apparently on the back of the plug to the cluster.