It started out as a water temp gauge now and then acting erratic and I thought it was the water temp sending unit and I changed it 2 or 3 times, then cut and soldered on new terminal end at the water temp sending unit, that didn't fix it! Then I noticed when resetting my trip odometer it would clear both instead of the selected one...Then sometimes when I started up the tach was bouncing around 1000 rpm and stay there the odometer would read 999999, the speedometer wouldn't work, the fuel and water temp would be maxed out! Then you shut the engine off and restart it everything was fine and working properly...I looked at the connectors, the pins, the printed circuit, wiring, and never could find anything obvious! Well I decided today to swap out the instrument cluster with another and it fixed everything! I figured that it had to be the instrument cluster with all that going on...Anyway I thought I would pass that on guys! so you don't chase your tails around in a circle, like I did!

 

Wow that is crazy! I wonder that would've happened inside the cluster to cause the problem. I take it you have a 98 or 99 since you seem to have the digital odo. (the 95-97 still used a mechanical odometer)

 

Yeah it's digital! I looked at the circuit board and maybe some corrosion on the speedometer grounds the silver solder looked a bit dirty/corroded I chunked it and threw in a 99 spec and it works perfectly and I cleared my speed sensor, AT communication codes. i'll test that out tomorrow during my driving! It's great to have a fuel indicator and speedometer working now. I was worried about speeding and getting too low on gas during my aircraft maintenance runs which are between Houston , La Grange, Seguin, San Antonio, marble Falls, Kerrville, Beaumont, and sometimes Jasper...This is a road dog and I must say 4th Gens are well built and reliable!

 

The same thing happened to mine and after the all 9s its been ok. My gas gauge is off. I know this sounds like BS but my odometer is 3000 less than before.

 

Mine's off by more than 100K...I just not it to work...