roymeyer Report post Posted November 3, 2011 Hey guys. I have a 7500 Onan diesel generator that runs for a minute and shuts down with a high coolant temperature fault code, but the coolant level is good and nothing feels hot, just warm. I went ahead and changed the fuel filter and air filter hoping for an easy fix but the same problem exists. The owners manual is of no help at this point. There is only 223 hours on the unit, which is in a 2005 Fleetwood Expedition. Any help would be appreciated. Thanks, Roy Share this post Link to post Share on other sites
MFERRALL Report post Posted November 4, 2011 I HAD SAME PROBLEM A COUPLE OF YEARS AGO. REPLACED TEMP SENSOR. CURED PROBLEM..(.WOULD SHUT DOWN IN LESS THAN A MINUTE.) Share this post Link to post Share on other sites
roymeyer Report post Posted November 4, 2011 Thanks, next question....where is the sensor located and can I get to it? The Operators Manual is no help. Share this post Link to post Share on other sites
johnctysonfmca Report post Posted November 5, 2011 Had this problem. Could be a defective coolant sensor. Not an expensive item if you are capable of performing repairs. Share this post Link to post Share on other sites
johnctysonfmca Report post Posted November 5, 2011 If my memory serves me correctly you will find this sensor screwed into the thermostat housing. I think the thermostat housing is attached to the cylinder head on the back side of the engine (the side where the water pump and belt is located). Also here is part number if you have one of these generator models, HDKAH/J/K/V/TU. Part number 193-0318. It will be necessary to remove the top cover from the generator in order to gain access to the sensor. Share this post Link to post Share on other sites