stargazr Report post Posted May 22, 2011 I have a Cummins ISL 400 CM850 engine, 2005 model. The temperature gauge does not work on engine start-up, then, as the engine heats, it will come on, and indicator needle bounces around, periodically. Sometimes the gauge will stop working after it has been working for a while too. Is there a relay in this system I need to look at? I have just purchased this coach, and have already replace relays for the air horns and a relay for the air dump. Engine temp sensor? Wiring problem? Bad Gauge? What would you experts look at 1st? Can I use a meter on the back of the gauge to see if I am getting a feed from the sensor, or should I go ahead order a sensor? Any advice would be appreciated. Thanks Share this post Link to post Share on other sites
wolfe10 Report post Posted May 22, 2011 The coach/chassis maker generally select and install the gauge package, not the engine maker. So, contact Monaco for advice on troubleshooing-- they can walk you through identifying if this is a sender, gauge, wiring or interface issue. Brett Share this post Link to post Share on other sites
