QuestionQUESTION: A few weeks ago my radiator fan stopped running, even when the temperature gauge shows very hot. I can hear the coolant bubbling as it goes into the overflow reservoir. The AC fan runs, and the AC is cool, at least until the engine hits max temp. I've recently flushed my radiator and put in new coolant.
What do you think the most likely culprit is? I tried pulling out the relays, but I have no way to tell if they're bad other than just replacing them. Could the coolant temperature sensor to the PCM be defective? Thanks for any help you can provide.
ANSWER: Hi, Michael. I'll need the year and the model of your car to give you more definitive information, but in general, if you have two radiator fans, both will normally run when you turn on the a/c. You might check the slow blow fuses to be sure that none are blown. You might also check to see if you have power and ground at the non-turning radiator fan connector when the a/c is on. If you have power and ground there but the fan is not turning, then you know the fan motor is defective.
Again, do follow up with the year and model so I can look at the appropriate schematic for your vehicle and advise what the most likely issues will be.
---------- FOLLOW-UP ----------
QUESTION: Thanks for the follow up.
I did some more testing today, and I found out something interesting. With the AC on, the AC fan runs, and always runs, even if the AC isn't blowing cold (again, I just think the car is too hot for cold air). What was interesting is I spun the radiator fan (non running fan), and it kept going, like a pinwheel in a breeze, and slowly slowly spun faster on its own. It kept going, losing speed and gaining speed incrementally, but never reaching its full operational speed. When the AC was turned off, the AC fan continued to run to try to cool the engine, but the radiator fan stopped. It repeated the previous behavior when manually spun again. My hunch is that the motor is going out...what do you think?
My car is a 2000 Hyundai Elantra, 4 cyl 2.0 liter with automatic transmission.
AnswerI think you're on the right track. Remove the fan in question and inspect it. You may find that there is a problem with the attachment between the blade and the motor, causing the motor to turn properly without the blade following in turn. If not, you're probably exactly on the money with the fan motor.
