Temperature Gauge Showing Incorrect Temperature

[soewhatman]

Having an issue with the engine temperature dummy gauge on an '04 Limited. With engine off (and also with battery disconnected) it is reading at about 1/2. When I start engine and it warms up, needle moves up to nearly red. OBDII scanner shows PCM ECT reading is correct, so temperature sensor is working fine and problem is isolated to the dummy gauge, wiring, and control module for that. All other dash gauges are working fine. If I disconnect the battery and tap on the gauge it moves up to red, even when the engine is cold, which I find strange.

It seems like the zero point of the gauge has been reset to the 1/2 way mark, and it goes up from there. It is working and moving the way it should, just starting from the 1/2 way point. Cooling system is working fine, engine does not overheat, and PCM is reporting proper coolant temperature.

I have had the battery disconnected and was adding in some accessory circuits and re-looming existing wires in the engine bay where loom had disintegrated over time, so I have been mucking with the wiring. I was very careful and tidy, but I still could have messed something up somewhere. Problem showed up after hooking battery back up.

Anybody ever had a similar problem? Any way to reset gauge to zero? Is the gauge done for and I need to replace the instrument cluster? If it's done for, any idea why so I don't repeat? Any ideas.

Thanks.

 

[Billwill]

Some previous owner probably took the instrument cluster apart.

When doing this it is very easy to dislodge a pointer on one of the gauges....putting it back in place is a bit difficult but with power Off it can be done.....probably been re-fitted a few degrees out!
Seems like the needle on the gauge is physicaly a few degrees off!

Once you have it all together and plugged in you can excercise the cluster by holding IN the Odometer Reset plunger while turning ignition ON. All gauges move about and all lamps light up. This is not a diagnostic but a test.

 

[soewhatman]

Some previous owner probably took the instrument cluster apart.

When doing this it is very easy to dislodge a pointer on one of the gauges....putting it back in place is a bit difficult but with power Off it can be done.....probably been re-fitted a few degrees out!
Seems like the needle on the gauge is physicaly a few degrees off!

Once you have it all together and plugged in you can excercise the cluster by holding IN the Odometer Reset plunger while turning ignition ON. All gauges move about and all lamps light up. This is not a diagnostic but a test.

Perfect thanks. Whatever happened was on my watch, as it was working fine previous to my electrical project. You pointed me in the right direction. Pulled the cluster out and was able to reset the needle position, which I didn't realize was possible. I figured it was all a sealed non-serviceable assembly. Working properly now.