Radiator fan relay
Hello, Chris. I will try to help you out with some pointers, but without a wiring diagram I can only go so far.The procedure for checking the cooling fans is to first check the fan itself and the fan motor. Spin the blades by hand to make sure it is free wheeling. Then check motor with jumper wires to make sure motor is good. If it is, find the fan relay in the under hood fuse/relay block, the cover of block should show relay locations. Pull the relay out and check that one terminal for the relay has power. This will be a "hot at all times" power signal. Use a voltmeter or test light to find the one hot terminal. If no terminal has power there could be a failed fuse link or maxi-fuse that feeds the relay. If one terminal does have power, then swap relays to check that relay is not the problem. Often manufacturers use the same relay (same part number) for different applications. Relays can be tested to some extent with jumper wires connected to the relay's coil side, then checked for continuity on the power side, but the only way to be sure is to swap in a known good one. Actually, relays only rarely fail, but never know without checking. So if you have swapped relays, will need to run engine until warmed up to see if fan cycles-it should come on for a few seconds after engine has reached normal operating temperature. If it does, you are good to go.If still nothing, we are about at the place where a wiring diagram will be needed, as I stated at the beginning. Manufacturers use different ways to turn the fan on by activating the relay. The engine computer will send a signal to the coil side of relay when it senses coolant temperature needs the fan on to increase air flow through the radiator. This often happens in stop and go driving, or driving at slow speeds. When relay coil is on, relay contacts on power side are closed and power passes to the fan motor. It's that simple, but the relay's coil side has to go to ground somewhere, somehow for the coil side to energize. Sometimes, the coil signal may be grounded internally by the computer. See what I mean: you need a wiring diagram to fully scope the fan circuit. If you get this far and still no fan, might try a new coolant temperature switch or sensor just to see if that is the problem. I hope this is of some help. Good luck. Post back when you have solved it and let us know.