Electric fan comes on too early
05-08-2010, 11:21 PM
#1
Teching In
Thread Starter
Electric fan comes on too early I have install an electric fan on a 2002 5.3 vortec that i swap into my 55GMC truck, used HPT to turn fan on at 200 degres but the fan comes on early before the thermostat is even open. The scanner shows the temp at 200 but the temp gauge is only at 180 and the lower rad hose is still cold which tell me the thermostat is not open yet. I have check the engine temp with a laser temp gauge and its at about 175 when the fan comes on. Any advices? Thanks
05-10-2010, 11:32 PM
#2
TECH Resident
Can the thermostat be stuck, and the water temp in the head actually be at 200, but if the thermo is stuck, it still is not allowing water to circulate. The PCM controls the fan, it reads from the temp sensor regardless of what the gauge shows.
05-11-2010, 06:23 AM
#4
Teching In
Thread Starter
I 'll be testing the stat today to find out if it open correctly.
