Engine fan controller problem

rd

Founding Member
Jan 12, 2000
3,316
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109
Ocean Springs MS
Drove the 89 notch tonight, and found no ac and no engine fan. Worked fine and blew cold Sunday night.

Pulled the new connector out of the new cooling fan control module, and it is also melted. Put the old module in and it works fine.

With the fan running, the bat wire to the module and the power wire to the fan get warm to the touch.

I have checked grounds, etc and am going through all that again.

Anyone have this problem and know how to fix it?

thanks, rd
 
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The easiest way I would recommend is to install a stock Ford relay to supply the actual power to the fan. Use the power currently (no pun intended) coming from the module to activate the relay.
 
i also have cooling fan issues

on my 92 lx hatchback the cooling fan only comes on when my ac compressor is engaged

if the ac isnt on the fan never comes on so i have to be moving all the time to keep air flowing through the radiator

i keep the heater on to help keep coolant temperatures down but i have no clue as to why the fan doesnt come on :shrug:
 
I had the same problem with my '87 2.3L w/o A/C. Couldn't find a new controller, and the wire was getting too hot anyway. My solution was to completely re-wire the system. Now the fan runs any time the car is running. I haven't had any problems, but then again it isn't that hot here in Sea-town. If you find out why the wire is so damn hot I would love to know. This car is my daily driver and I would prefer to fix it the right way.
 
The cooling fan module on my 89 is under the dash to the left of the steering wheel, on a metal bracket and has an 8 wire connector going into it.
It is a small black plastic box.

This one is called a cooling fan control module. It contains a circuit board with two relays and a solid state relay device. It turns the cooling fan on and off based on a temp sending unit, and the ac input. It also has a timer function that delays fan start on certain occasions. Supposedly it may also turn the fan off at higher speeds with no ac demand.

According to Chiltons, it turns the fan on at 221 deg F, for cooling, with no ac demand.

The later cars upgraded to an IRCM, integrated relay control module, which is under the hood on the pass strut tower.

I installed a bypass 30 amp relay. But I melted a 30 amp inline fuse holder just testing it. It is now wired with a 30 amp circuit breaker, the 30 amp relay and 10 ga wire. Awaiting a 40 amp relay. It seems to work, and the control module does not seem to get hot anymore.

With the fan running, my old inductive ampmeter indicates 30 to 40 amps current in the fan wire. But it moves a hurricane worth of air.
 
Forgot to mention that it also operates the ac clutch, based on input via the ac pressure switch. It is also wired to the eec 4 module, I think.

Took a lot of research online, in the Chiltons, and in the Ford Fuel Injection book to get this far.

As I posted earlier, Ford sells the harness connector repair kit, and the replacement module.

Subsequently, I found that they are available aftermarket. The module is a GP Sorenson MR121, and the Harness Repair kit is a Factory Air 37212. Both are available at Carquest. Advance Auto listed them, but the guy said they were not available via the store, only online. Mine are on order at Carquest.

This seems to indicate that there is a problem with these, or at least the wiring or current draw of the fan motor.

Anyone else have any insight or history on this, or how to fix it?