Author Topic: Low Coolant Sensor  (Read 2363 times)

Joe Lenhart

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Low Coolant Sensor
« on: July 30, 2013, 01:46:02 PM »
Last week I replaced my low coolant sensor.  I did this because the light and alarm was on.  Problem solved.  Everything worked great.  The motorhome sat for a week and now I have the exact same problem.  The sensor goes into the bottom of the surge tank and there is plenty of coolant in the surge tank. When I took out the old sensor it was clean so I don't think dirt or sludge is a problem.   I am wondering if this is a wiring problem.  Any suggestions?

Joe
91 Contessa
3116 Cat

Edward Buker

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Re: Low Coolant Sensor
« Reply #1 on: July 30, 2013, 05:10:20 PM »
Joe,

Usually these sensors have a resistance range of operation with and without fluid on the sensor. You could look for literature on that sensor from the manufacturer, take some ohm measurements and see if it is wiring or the new sensor that is at fault. One of the wires on it should go to ground. You could measure from that wire to a metal chassis ground to see that you are getting a good ground. If the tank is metal and that is used as a ground be sure that the sealant on the plug, Teflon tape or otherwise is not fully insulating it. Could be that you got a bad sensor as a replacement. The hot lead to the sensor will have a voltage on it with the ignition on, you could measure that voltage and have someone else with the same tank sensor take measurements to compare. Hope this helps.

Later Ed