I have a weird instrument cluster problem in my '04 GT 6sp. Hoping someone can shed some light on what could be causing it and maybe suggest a workaround fix.
Started as no illumination, no ODO, no gauges (speedo, tach, temp, fuel). Everything else worked OK including the instrument panel indicators like turn signals, hi/lo beam, ABS, CEL, BRAKE, OIL, SRS, etc.
Checked all fuses, especially AM2, GAUGE and DOME, all were good, replaced with new fuses anyway, no change. While I was replacing the fuses I stumbled on some strange behavior:
When I pull the DOME fuse and leave it out, the instrument panel starts working again! Speedo, fuel, illumination and all! Sometimes the gauge needles jump to 50% for a second when I first turn the ignition key. Other than that the whole instrument cluster works great...I drove the car like this for 2 weeks and the instrument panel worked fine the whole time. Of course with the DOME fuse removed I have no power to the radio, dome light and remote door locks which kinda sucks.
When I re-insert the DOME fuse, the instrument cluster only works until I turn off the car. After a few minutes with the key out, gauges and illumination go dead. I tried unplugging the Radio HU, no help. Another trick to temporarily bring the instrument cluster to life is unplugging the cluster harness and plugging it back in. Again then it works until I turn the car off for more than a few minutes.
I've been staring at the wiring diagrams but they're a bit overwhelming... My theory is that the DOME circuit provides permanent power to the instrument cluster, while the GAUGE circuit is switched. For some reason the permanent power connection is causing a problem in the cluster. I'm tempted to cut the wire providing power to the cluster from the DOME circuit rather than spend $$ on a new used cluster with incorrect mileage. Thoughts, anyone?