cooling fan motor

[pdoan_98]

In the process of replacing my heater hose, I discovered my primary cooling fan does not work. How hard is it to replace the motor? The blades are still in great condition.

Pat

[Ryan]

Its easier just to replace the entire unit. I'm pretty sure there are a lot of interchangeable rads from same-era 323/escort/etc.

How did you test to see if it was dead?

[pdoan_98]

I replaced the fuse first and the fan would not kick on. Can you tell me when the fan should come on?

[Ryan]

the easiest way is to let the car run, and then unplug the green coolant sensor. default on that sensor failure is fan on.

Another way, that assumes your TPS works, is to put it in diagnostic mode (jump TEN and GND with something metal like wire or a paperclip) and then blip the throttle by hand. If the TPS reads off-idle, the fan is triggered.


You can also apply 12v directly to the fan connector, if you're really old school

[pdoan_98]

Where is the green coolant sensor located? The same question goes for the TPS sensor? How can you tell if the TPS works?

[Ryan]

Sorry, I had no idea what level you're on with the car.

Assume your TPS works (throttle position sensor).

Find the DIAGNOSTIC box in the engine bay, little black box, says that on the lid. Inside, jump the pins TEN and GND with a little bit of wire or a paperclip. Turn the ignition to ON, no need to start it, and then just press the throttle. The rad fan should come on.

[pdoan_98]

If I do that, will that tell me the motor is bad or the tps sensor is bad? I have very little car exp. My brother does most if not all the work for me.

Thanks for all the help.

[pdoan_98]

Just in case, I have 94 mx-3 with a 1.6L motor. Where would the diagnostic box be located in the engine compartment?

[Ryan]

I believe all of them are driver side, against the firewall. (the wall between the passenger and engine compartments)

[wytbishop]

12V to the motor is really pretty easy. it's only a two wire plug. Jump one to ground and the other to the positive battery terminal. Even if you do it backwards it will just spin the wrong way.

If it doesn't spin it doesn't work. I have had a rad fan motor crap out on me on my first RS like 8 years ago...so it does happen.

[stepchyld]

The green coolant sensor, also called thermosensor, is on the side of the engine's head, just behind the distributor (the black cylindrical thing the plug wires connect to).
That heater hose you had to deal with, it's pretty close to where it connects to the engine.
If you stand by the driver side fender, look over the airbox at the side of the engine, about 3-4 inches to the right of the distributor and down a few inches, you'll see it.
The TPS is located on the throttle body, which is where the intake hose (from the airbox) attaches to the engine. It has a 4-wire connector, but I've yet to do anything to mine, so cannot advise further on it...

When checking a fan motor, I've always done what wytbishop described

[pdoan_98]

Got it. Thanks for all the help. I'll keep ya posted.

[pdoan_98]

All right guys.....Here is the update, I have replaced the cooling fan motor. The fan still did not turn on. In the process, I also replace the coolant temp sensor. What else do I need to check to see what would cause the fan to turn on? The mechanic did put a 12v power source to the fan and it does work. Any ideas??

[Nd4SpdSe]

Isn't there a relay for it?

[2fazed]

You can test the fan to see if it's bad. Just unplug the harness and connect power and ground to it.