How To Test the Radiator Fan?

A quick and easy test you could do is just plug-in the OBD1 code reader, and the first thing it will do is cycle both fan speeds. If you hear the relays clicking but no fan, there's a good chance the fan itself is toast. But if you don't hear the relays clicking and also no fan, then the CCRM is the likely culprit, and wiring a manual switch could be your answer.

Oh and if both fan speeds work fine when you do this, look to the ECT sensor, mine did the same thing when it went bad... both times.

In addition to Stephane's wise thoughts.............

Lookin down at the fan from the hood (as opposed to being under the car), the top fan terminal is ground, middle is low, and bottom is high speed.

It's probably all stuff you know but here are a couple of quick tech notes:

One. There's a little info in the middle of that one which might apply.

Two

I will also note that the fan can pass the self test (you hear both speeds cycle) but in it's true dynamic, one or the other speed wont come on. A couple of times I've seen high speed not come on with the AC (instead low speed continues to run when high should be running).


Good luck.

Also the high speed fan will come on when the A/C is turned on, regardless of temperature.