Sammy,
We had trouble with our 2000 H Marathon coming back from Quebec. The temp guage would be fine reading around 195, then fling itself all the way over. The warning lights flashed, bells went off, then the guage would behave. No faults tho, on the DDEC info screen, tho
We later found out the wire to the sensor was loose at the sensor. Have you had any engine servicing done recently. If not, maybe your sensor is failing.
Jim and Chris
2001 Featherlite Vogue XLV 2 slide with Rivets-current coach, 1999 shell
Previous 22 years,
We have owned every kind of Prevost shell but an H3-40