Another Dash Gauge Issue

[Richard Davis]

I have a 2006 Monterey with the CAT C9.  My dash coolant temperature gauge is no longer functioning.  I either have a failed gauge or a failed sensor (or a ground issue in the dash, but all my other gauges are functioning correctly).  Does anyone know if the dash gauge uses the same sensor that the ECM uses (the ECM temperature is displayed correctly on the Alladin display, so the ECM is getting correct information).  Can someone point me in the right direction to locate the temp sensor on the engine that is used for the dash gauge?  I "assumed" it would be on or close to the thermostat housing, but a cursory inspection did not identify it.  Any insight into troubleshooting whether it is a gauge problem or a sensor problem?  Thanks!

Richard

[Steve Huber Co-Admin]

Richard,
Normally they use separate sensors for the ECU and dash. I think yours should be the same. If you aren't sure of the dash sensor location, get the wire # from the one that connects to the dash gauge. That will tell you when you locate the suspected sensor on the engine.
Steve

[Richard Davis]

Followup:  I am still trying to locate the sending unit that provides the status for the dash coolant temperature gauge on my 2006 CAT C9.  The sending unit on the rear of the head on the C9 provides information to the ECM and to the Aladdin, but not to the dash gauge.  I have tested the gauge and it seems to function correctly.  It has 12 volt power and evidently receives metered ground connection from the sensor.  I do not know where to look for this sensor.  It does not seem to be on the engine itself.  Since the side radiator and associated plumbing was added by Beaver during the coach build, I suspect it may be located somewhere in that plumbing.  Does anyone know where specifically I need to look to find this sensor?  It seems to be hiding from me.  Thanks.
Richard