QuestionRoland,
I recently replaced the thermostat and flushed the radiator.
shortly after the fan just stopped blowing, I checked the fuse and it is fine. What should I check or replace next. I have heard there are two possible issues, relay or resistor however I do not know where they are located or how to test. Any assistance will be appreciated.
AnswerHi John,
I assume that you are speaking of the radiator fan, not the heater blower. Let me know if otherwise.
It is possible that the fan is not coming on because the engine coolant is not getting hot enough to call for the fan. If you try the A.C. the fan should automatically come on; or if you remove the plug on the temp sensor located on the thermostat housing box that too should cause the fan to come on. If neither does that, then I would start at the fan and try jumping 12V from the battery to the light green wire at either the fan plug or the fan control relay. The relay is located on the left inner fender shield, the rearmost of three on that side of the engine compartment.
Then too, you should hear the relay click (or feel it click since there will be click from the middle relay as well for the A.C compressor) when the A.C. is requested by a helper in the cabin while the engine is running. If the relay doesn't click, then try switching the relays if they have the same part number, to test for possibly a bad fan relay.
There is a 20 amp in-line fuse (in a gray color wire) for the fan motor and compressor clutch located near the battery wire that has a bundle of solid color wires attached to it (the fusible links). Is that the fuse you checked? Finally is the question of the relay control which is actuated by the coolant temp sensor which must drop to below 1,000 ohms for the engine controller to actuate that relay.
You could also check for fault codes that the engine controller may have recognized and stored in the memory. Turn your ignition key "on-off-on-off-on and leave on" doing this in 5 seconds or less. Watch the check engine light which remains on to begin to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat to verify the counts. Then group the numbers in pairs in the order of appearance to form the two-digit fault codes. Then go to www.allpar.com/fix/codes.html for a translation of what the codes mean. 55 is always the last code, it means end of readout. Maybe one of the codes will tell you which circuit is the problem.
So those are the items I would check out. Let me know what you find out or if you have any questions.
There is no resistor in the fan circuit, but there is one in the heater blower circuit, called a resistor block. But I assume that is not what is wrong.
