Cooling fan wont turn on

Discussion in '2.3L (N/A & Turbo) Tech' started by GT40 2, Jan 23, 2009.

  1. I have an 89 Mustang with a cooling fan that wont switch on. The car gets hot during low speed driving. The fan motor isnt the problem since I jumped it and it ran. So I went and got a new tempature switch (the one in the bottom of the intake manifold) and it still wont turn on. In my chiltons manual it says that the fan is supposed to turn on at 221 degrees. The only way to get the fan to work is to ground it out, but then it runs all the time.
  2. Well, when you say the car is "getting hot," what temperature is it at? Do you have a temp gauge of any sort?

    The factory fan does not come on until the factory gauge is up into the red at the very top of the gauge.

    You could just hook it up to a toggle switch.
  3. fan

    Check the fan controller module. On an 87 it is near the top of the driver kick panel. They have a tendancy to burn up. If that is what it is then the 4th pin will probably be burnt and the connector will be melted. This is can be caused by the fan drawing too many amps for the relay in the module, or just plain under engineering.
    If that is the problem you will need to replace the fan module and connecter. The connector can be difficult to find. you will need to find out if it is a 8 or 10 pin.

    I also had a problem in the fan circuit wiring. There is a four pin connector near the rear of the driver shock tower that the fan circuit runs through. I think it is an orange wire with a tracer color I cannot remember. Check the pin in that connector to see if it is burnt or loose.

    For a little extra dependability I would add a relay under the hood to power the fan. That way the amperage to run the fan wont be running through the fan module and it wont burn that up again. Just use the fan power wire (the one previously mentioned) for the low side relay signal. Make sure you get a continous duty relay .
  4. Hi,

    Did you check the actual Fan Relay? Id swap it out with another Relay of the same Amperage or, buy a cheap OBD1 Scanner and do a KOEO self test.

    Or you could try jumper the Fan via the relay if your comfortable in doing those tests. Even if the control circuit of the relay is good, the points inside the relay may be bad thus not activating the circuit.

    A test light would also work wonders here too.

    I have a 93 Stang with one of those CCRM so my Fan, AC and FP Relay are all housed in one unit, so if one of those relays of mine goes, i have to replace that whole CCRM....which has happened once to me allready.
  5. fan relay

    The fan relay is in the fan controller module I mentioned earlier. It is housed with the a/c clutch relay and controls the fan when the a.c is turned on. It also has inputs from the fan switch and controls the delay from when the a/c is turned off to when the fan shuts off. If the fan relay is bad in the module you will be able to see it and smell it. the relay will be toasted and may not be able to unplug it without breaking the connector.
  6. mine had the same problem but i found a switch right by the fuses box under the dash that turns it on i don't know if thats stock or anything...