I drive an old mack tractor truck to pull a side-dump trailer for work.

The problem is that for some reason the speedometer and odometer only work intermittently. Whenever I have to stop the truck (ex. stop light) the "Electronic Malfunction" lamp comes on and the speedometer & odometer quit working.

Then, it takes a while and usually it will start working again after the truck has been running at highway speed for a while.

Anybody know what this might be??

Please advise.

Thanks!!!