tinmansc

1991 C4 L98 auto with 55K on the clock. Just replaced the water pump, and a few incidentals. Runs and drives pretty well. Been having this problem for a few years, figure it was about time I asked about it. I've searched and search, cannot find anything relevant. When driving around as normal, the dash switches from mph to km/h incessantly. It never switches from km/h to mph, only the other way around. If it's displaying km/h it will happily stay there forever. When I manually switch it to mph using the eng/metric button, it will switch back within a minute or so to km/h.

At first I thought it was just the button acting up, but if it were the button it would sometimes switch from km/h to mph, but it does not. Is there a default setting that gets programmed somewhere that I'm missing? Does it switch back to it's default after a minute or so? If so, where is it?

Appreciate this forum and all the help it's given this lurker.

HlhnEast

I would think your switch is going south. You might try some electrical contact cleaner to see if it will help. It may make it worse by cleaning out dirt that is holding stuff together but generally it works. Worst case you will replace the switch.

Cliff Harris

This kind of problem can be caused by switch contacts that oxidize over time and stop making contact. That's why contact cleaner can fix something like this. It's also possible to fix it by switching back and forth many times to wipe the oxidation off the contacts. Your best bet is to do both...