Erratic Readings on Oil Pressure and Speedomoter

[K5EAG]

I have a 2000 Winnebago Journey WKP34B with a Cummins engine.
At various times my oil pressure guages jumps around, goes to very low pressure, moves up to normal, then back down. Anyone had problems with the guage or sending unit on the engine?
Next problem: Speedomoter - sometimes my speedomoter just stops and the meter drops to zero. After a while it comes back and registers normal speed. Could this also be a bad meter, or bad sending unit on the engine/transmission, or where it senses the speed?

[Caemlyn]

Both sound like faulty ground connections to me. I'd start there

[Martind4]

If your rig is on a Freightliner chassis, it should have a VDC (vehicle data computer). The VDC collects engine and transmission data, converts it to digital and sends it along on a data bus to your gauges on the dash.

If one or more of your gauges are acting up and its not ground related, then I would suspect the VDC. There are other posts on this forum for the VDC repair procedures if you are comfortable with a soldering iron.

The Freightliner Help Desk at 800-385-4357 can help diagnose problems, have your VIN# ready.

[K5EAG]

Thanks Denny for your answer. Yes, I am comfortable with a soldering iron. I will look for other posts as well.

[ebg338]

My Winnebago did the same sort of thing. Mines an older model on a P Chassis (7.4 lt Chevy engine). This issue with the pressure gauge jumping around on mind was the pressure sensor at the engine. Took about 20 minutes to replace and was about $20 if I remember right. The speedometer jumping around on mine was due to a loose negative battery cable. I'd check that first, quick and easy. Good luck.

Bill