rad fan?

james5275

Registered User
Hello fellas.
I just replaced the engine in my 89 5 speed. Everything is good but the radiator fan wont turn on. I jumped the fan to the battery, both low and high speeds work there. I robbed the relay box (behind right headlight) from my 90 sc (same numbers) and still doesnt work. I called my ford dealer and asked them about the coolant temp switch and they couldnt tell me if the car even had one. when i bought the car, the engine it wasnt running. Any help here? thanks.
 
Rule #1: No one at Ford knows anything about these cars.

Okay you have verified that the fan motor is okay. Are you sure that the IRCM from your other car is okay? Does your fan turn on when you have the A/C on? Now regarding your main question, yes of course there is a temp sensor sending info to the EEC. There are two on the engine (unfortunately I cannot remember which feeds which), one goes to the instrument cluster gage, and the other relays info to the EEC. Unfortunately my reference material is 50 miles away and I cannot look up which is which. Hopefully someone else can help guide you on that.
 
WHAT TO USE

go to the tech search, much has been writen on this ..................cut the 14 wire outside the rcim should turn fan on when key is on.......................FAST FREDDIE:cool: :cool: :D :D
 
ircm

The IRCM is good from my 90, fan kicks on fine in that car. I am assuming the temp switch is on the right side, near the TB. Has 2 wires. Is there a way to check that switch?
 
It's not a switch it's a sensor. It's located at the thermostat housing and is the one with more than one wire going to it (the single wire one is for the gauge). Try turning on the AC with the engine running. You can also do a search. I don't recommend cutting wire 14. Figure out what the problem is don't use the "coat hanger and duct tape" method of car repair.

Jeff
 
fusible link

Check the wires coming off the starter relay on the drivers side inner fender panel. One, I believe black, is power for the fan. It has a fusible link section real close to the relay. Look to see if it's burnt up. If it is, I think your fan is drawing too many amps and is ready to go out completely. If memory serves it is a 16 ga link. John
 
....

the Coolant Temp Sensor is by the TB , i have a Autometer gauge on the Coolant Sender Wire for the gauges witch is on the thermostat housing wich is a 1 wire not 2...Take a meter and start your car and take the connector off and see if you get power to the clip before the fan, but becareful not to overheat because..i just did this myself because i thought my low speed wasnt working but i verified it by checking it with the meter, i guess i cant notice the difference when the low speed switches to high speed..i just recently ran a switch (temperarily untill i get dual fans with adj temp switch/custom radiator) to near the top of my hood by the wipers, i just kick it on before i drive around, useing the low speed power wire, fused it with a 30 amp fuse and connected it to the side fender relay on the drivers side, and grounded to my custom ground spot i have near there, now i noticed my temp is so much lower, my car used to idle and hit up to about 228-230ish and now at idle it only goes up to 210 tops..for not much work this is a good mod (could run it inside but mines only temperary) it helped me 20 degrees at idle and driving around usually doesnt go past 210 either..
what would be better is to make 2 switches inside your car, that run to each low and high speed so you could start the fan on low speed then switch to high speed so you wont burn out the fan motor, someone should make a cuircut of that without switches so you never have to worry about switching it on just hook it up to an acceossary so when your cars on it engauges the low speed fan the about 10 seconds later stop the low speed and engauge the high speed fan all the time ..that would be cool..cheap mod and nice performance...Alex LaChance..

From MN12Performance.com

Cooling fan motor will run at low speed:

If engine temperature is higher than normal. Cooling fan motor starts running at 106 *C (222 *F) and stops running at 101 *C (214 *F).

If A / C is on and vehicle speed does not provide enough natural airflow. Cooling fan motor starts running at speeds at or below 69 km/ h (43 mph) and stops running at 77 km/ h (48 mph).
Cooling fan motor will run at high speed:

If engine temperature is higher than desirable and cooling fan motor has been operating at a low speed.
At 109 *C (228 *F) and stops running at 105 *C (220 *F).
 
Re: ....

SuperCoupeSC91 said:
the Coolant Temp Sensor is by the TB , i have a Autometer gauge on the Coolant Sender Wire for the gauges witch is on the thermostat housing wich is a 1 wire not 2

Do you have a picture of the sensor by the throttle body? Because there are 2 sensors in the thermostat housing the single wire one is the gauge sender and the 2 wire is for the EEC. Is this a later model thing?

Jeff
 
...

i have a 91 SC and there is only one wire on the thermostat housing wich is for the gauges, and the temp sensor is located on infront of the first front injector facing the front of the car by the TB right next to some fuel rail lines......is your different ?
 
Jeff, I believe the sensor people describe as being by the TB is the temperature one for the computer that is actually in the manifold on the passenger side of the engine. Only the gauge sensor is in the thermostat housing. I think this is the same for all years. (I'll have to look when I get home tonight to make sure.)
 
sensor

On my 89 and 90, there is a single wire sensor on the thermostat housing, my manual says its for the temp gage. the 2 wire sensor is on the intake manifold about 1/2 inch from the DIS module. Lucky me, my haynes manual doesn't say how to troubleshoot this circuit, "take it to a dealer". I checked the fuse link, its in good shape.
 
A/C

I knew I forgot something. But the a/c system is not charged. Will that still send the signal the brain if the compressor isnt engaged? Sorry If I,m wasting your time. Always learning something new with these cars.
 
Not real sure.

My car would turn on the fan, and I know there wasn’t any freon in the system. Just try it and see. Unplug the compressor there is a 2 pin plug right on the top of the compressor.

Jeff
 
A/C on still no fan

well, Im about to do the old #14 wire trick. Only thing I havn't done is swap the brain from my 90, hopefully they are the same. Any other ideas anyone?
 
Did you have the engine running?
Did you check the fusible link? Sometimes the fusible link will burn and not damage the insulation. Meaning it will look just fine but if you grab it, it will feel like an empty tube.
Have you checked for voltage at the main wires from the IRCM?
It’s the black/orange wires, and it’s fed by the #2 fusible link don’t know how to tell them apart.

Do a search for cooling fan or overheating. There was another guy that had the same problem but I don’t remember what the outcome was.


Jeff
 
Last edited:
Back
Top