I replaced the thermostat 1st, has never boiled over so thought maybe gauge was wrong, installed AZ temp guage, hooked up cooling fan direct. No temp difference. Does not lose any coolant. Timing has been checked. Thinking maybe radiator partially plugged or water pump bad. If the temp is actually 235-240 degrees, why doesn't the radiator fan come on? I am temp rigging a 12v light parallel with the fan motor. If power goes on to the fan, while driving, I will see the light come on. Just an idea. As an after thought, I just disconnected the fan sensor on engine, shorted the two leads going back toward the fan relay, turned on power, but the fan did not start. Works on a short. Doesn't it? How do I check the fan relay?I am retired with lots of time. Truck is for fishing trips.
Friday, April 16th, 2010 AT 12:40 PM