Cooling Fan Issue

TSC89

SCCoA Member
First, I know this problem has been beat to death on the forum but I have read every post about this and found no answer.

I have a 1989 SC automatic and radiator cooling fan never comes on except when tested by a OBD tester. I have tested the fan speeds directly and have low and high speeds. Pulling the A/C connector while the engine is running does not activate the fan either. The code pulled during OBD test was the one for the ECT but I have already replaced it twice, cleared the code and the fan still does not activate. I have already tested the wiring going to various sensors and the ECA. I know I can cut the #14 wire and tie it to #17 but if the high speed does not come it does not matter.

Could the ECA be going bad and not activating the fan?

Thanks.
 
I would first try unplugging the ECT....

This should make the low speed fan come on along with a CEL.....

Cutting the #14 wire makes the low speed fan run when the ignition is on....

It sounds like your IRCM might be bad......

I just replaced mine this weekend.....
 
I have already pulled the ECT connector, no fan and no CEL. I went ahead and replaced the ECT sensor.

I read the other posts about cutting wire #14 to turn on the low speed fan. In other posts it also says to jumper it to wire #17 to disengage the low speed when the high speed comes on so you don't burn things up.

I tried a working IRCM out of my other SC and still had no fan. Both IRCM's work in the other SC.

I will check the wiring again.
 
On my car (92) I left 14 alone and grounded 17. Ran the high speed all the time and I never had a problem. My friends 94 we did the same thing and he had the wiring harness melt from the current draw. So we reconnected 17 and just cut 14. I did the same to my 92 and now the low speed runs when the ignition is on. It never gets hot except on the highway but I have no front air dam.

On my 90 I had 14 cut but then it stopped working one day when the fan motor burnt up. I replaced the motor, and the wiring was ok, but the fan never worked. I cut the harness on the car's side (not the fan connector) and wired in a 30 amp relay to the low speed power wire. I now have a switch on the dash I can flip on if the car gets warm. I have no way to turn on my high speed and it never works. I know the motor is good. The low speed fan never lets it get too hot so I just don't worry about it.

By not cutting the fan motor's harness I can swap it out if I ever have a problem because I have a lifetime warranty on it and I don't want to get questioned about why the connector was cut. So I just cut before the quick disconnect.

I don't know about splicing 14 and 17 together. I'd just put a relay and a switch on the low speed if I was you. Then you can control the fan.
 
Buy a flexalite high performance fan from Victor at spinningwheels.com it fits in the stock shroud and run an adjustable fan switch.Then it bypasses the ecm.That's what I put on my car and it runs much cooler now plus you can hook up a toggle switch to the relay on it and run you're fan at the track in the staging lanes while you engines shut off to cool it off better.

Jay
 
You might have a bad fan motor.....

Have you tried applying direct current to the fan motor to see if it works????
 
Yes, the fan motor was the first thing I checked, for both low and high speeds and worked fine. I am picking up a 3rd IRCM tonight.
 
Last edited:
Just for follow up in case anyone else has this problem. The problem was the ECT sensor . I went through 3 IRCM's and 2 new ECT sensors to fix this problem. The car now has the original IRCM and a new ECT sensor. The first new ECT sensor was bad out of the box.
 
The first sensor came from O'Reilly Auto and the second came from RockAuto.com.

No, there was no Check Engine Light and I did check the bulb to make sure it was good.
 
Isint thier fusible links going to the fan? I dont know if that means there is fuses or that you can add fuses, but its something to consider.
 
Back
Top