Recently I noticed that the fan on the radiator does not function, resulting in overheating when using the AC. I have tested the electrical wire leading into the fan motor and found that it is putting out 14.4 volts, indicating that the wire is functioning properly and that all fuses are intact. I also hand spun the fan to see if it would turn without resistance, which it did, indicating that the motor is not jammed.
These tests lead me to believe that I may need to purchase a new fan unit and install it. My local sleeze shop wants $250 to do it, however I have found I could do it myself for $70 and an hour or two of my time, much more efficient.
I would like to know if my assessment of the situation is correct, and if I should go ahead with purchasing and replacing the fan? Additionally I have found that there is a dual fan option for my vehicle, and I was wondering if I should purchase that instead of the standard one fan?
Since you are getting 14.4 volts to the fan then I would run a temporary ground to the fan and see if it runs. If it does then you may have a faulty component between the fan and the ECM. The trigger signal from the ECM is a ground in all likelihood.
Pull the connector off the fan and find the common (ground) wire by using an ohmmeter. I would leave the connector disconnected and run the fan directly from the battery. You don’t want to accidently fry your ECM. If you are not sure how to do this then have a knowledgeable friend help you out. Keep your fingers clear of the fan because they start suddenly and you want to keep all of your digits on your hand.
@missileman is saying just b/c there’s 14 volts going to the fan, even if the fan is good, it still might not run. There has to be a path for the return (ground) current too for the fan motor to spin the fan. And that path might be what is used by the computer to switch the fan on and off; i.e. a fan can be turned on and off with a switch in the power side of the circuit, or the ground side of the circuit.
Usually the computer wouldn’t provide the ground path directly, it would be done w/a separate fan relay. And the relay could indeed switch the 14 volt rather than the ground, as you (the OP) are assuming. A wiring diagram for the car would tell you how this is wired on your car. If I were in your situation, that’s what I’d do first, secure a wring diagram somehow for the fan circuit. You might can find it posted on the internet, by Googling.
If you wanted to avoid damaging other stuff in the process of testing the fan, you could just remove the entire fan ass’y, and bench test it off the car. And if the fan is bad, you’d have to remove it anyway. Might be easier to do the testing. It depends if you have to remove the radiator to remove the fan ass’y.
My 2004 Ion has been through two fans and we’re about to put in the third. I don’t know why, no one can figure it out, everything seems to be working just as it should and putting out the correct volts. Replacing the fan is a big pain in the tukas! My husband’s 2002 Saturn wagon was MUCH easier, he could just replace the fan motor, but my Ion has the whole shroud and everything as one piece. We got one from a junkyard but it had a couple of broken bits and vibrated something fierce so I wasn’t all that sad to see that one die.
@Bcollyer … Sometimes a higher than normal resistance can build up in the power connector to the fan, due to corrosion or whatever. This causes a voltage drop, so even though the battery and alternator are ok, the voltage at the fan will be lower than normal. Depending on how the fan motor is designed, a lower voltage could cause the fan motor to attempt to compensate for the low voltage and to draw more current than it normally would. More current would wear the motor brushes faster.
Easy to verify yes/no. Ask your mechanic to back-probe the fan connector when it is on, to see if the fan itself is getting the full battery voltage.
