cooling fans not working

marcus

Registered User
neither fan kicks on and the car will over heat if I let it.
I replaced the coolant temp sensor and that wasn't the problem.

The main fan has 3 terminals on the connector. I was unable to find one terminal that was ground so I did not hot wire the fan, in fear of shorting it out.
Is there a temp switch also? and where is it if there is one?

Does any one know about the system?

Thanks in advance for any help.
 
Did you check all fuses under the hood and inside the car?. Also check for bad relays. What type of car do you have? Hope it helps.
 
cooling fan not working

I have a 94 super coupe. I did check the fuses. they are fine.I don't think the fan has a relay. ? There are 2 relays in the under hood fuse block. I swapped them and there was no differance. I'm not sure what those relays are for.
I did find another posting of the same problem and the solution was to cut a wire and make the fan run when the key is turned on. I would like to fix what the problem is verses the alterative if possible.
 
search... there are many threads related to this. The fans are controlled by the engine computer based on an input from the A/C pressure and the coolant temperature sender. If A/C is turned on , the EEC tells the Constant Relay Control Module CRCM to energize the low speed winding of the fan.

If coolant temperature reaches 212f the eec tells the CRCM to energize the low speed winding of the fan. If the coolant temperature reaches 224f the eec tells the crcm to energize the high speed winding of the fan.

Test to make sure the fan motor even functions.
Then make sure your temp sender for the coolant is working (this is seperate from the one used for the gauge)
Then check for proper voltages/grounds on the signal wires to the fan.
 
And if all else fails, wire in a fan control switch. :cool: The EEC circuitry seems to develop issues as the cars age... which is not a good thing at all but it happens. If I ever figure out how to fix the problem w/o a switch or other external controller, I'll post it.

I'm wondering how many SCs have been junked because they overheated and blew the head gaskets. :confused:
 
94/95 Cooling fan information

94/95 Main (puller) Fan Wiring Colors
Blue - Low Speed
Black/Orange - High Speed
Black - Ground

94/95 Auxillary (pusher) Fan Wiring
Blue - Low Speed
Black - Ground
White/Red - Low Speed (not used)

Early Model Fan Wiring Colors (for swap purposes)
Brown/Orange - Low Speed
Brown/Yellow - High Speed
Black - Ground

IRCM/CCRM Pin Outs (Main Fan Relays)
Pins 1/2 (black/yellow and black/orange) - Power to HIGH speed fan windings
Pins 6/7 (2 blue wires) - Power to LOW speed fan windings
Pin 13 (red) - 12V Ignition Hot (splice with 3A fuse if using external relays for fan)
Pin 14 (tan/orange) - Signal from EEC to IRCM for low speed fan
Pin 17 (green) - Signal from EEC to IRCM for high sped fan


Auxillary Fan Relay
Located on the DS fenderwell near the cowl/brake booster.
Red - 12V Key ON
Orange/Green - Trigger (ground to run fan at all times Key ON. Switch can be installed to open/close ground for manual control)
Yellow - Power from Power Distribution Box
Blue - Power to Fan

Power Distribution Block
Fuse (need to get ##) - 60A - Main Fan
Fuse (need to get ##) - 60A - Aux Fan

Testing Fans/Wiring
1. Check fuses!!! The main fan's 60A fuse likes to melt. I recommend running it off an external mega fuse and splice into the factory wiring.
2. Perform a KOEO Test. EEC will trigger low speed, high speed, then pusher fans to activate in sequence. Note what doesn't run.
3. Hotwire fan winding(s) that did not activate in KOEO test. If fan spins, you know it's most likely a relay or wiring.

Temp Solutions/Quick Fixes
Pusher Fan
1. Ground the trigger wire (Orange/Green) to run fan at all times Key ON. Switch can be installed to open/close ground for manual control.

Main Fan
1. Unplug the ECT (engine coolant temp) sensor. This will run the low speed fan at all times Key ON. It is located on the shaft that screws into the front, passenger side of the lower intake manifold. The passenger side heater core hose connects to this shaft directly beneath the ECT sensor.

2. Cut #14 wire in the IRCM to run low speed fan at all times Key ON. Switch can be installed to open/close circuit for manual control.

3. Splice #14 wire in IRCM to #17 to disable low speed windings (fan) when high-speed windings (fan) activate. This should be done if High Speed relay works in the IRCM and Low Speed is being run off a manual or thermo-electric switch. CAUTION - Running both windings at the same time will quickly burn out the fan and possibly cause a fire hazard/wires melting/additional electrical problems.

4. Splice the main fan's low speed fan wire (Blue) into the Blue power wire for the Auxillary fan. Ground the Aux fan relay as per above. This is best done only only when the IRCM or power to the main fan fails, but the fan motor itself is still functional.


IMPORTANT NOTE: EVTM manuals that state IRCM pin out 6/7 as the high speed fan windings are wrong. 6/7 (Blue wires) run to the low speed windings on the main puller fan. The black/yellow and black/orange of pin out 1/2 are for the high speed windings.
 
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I didnt read alot of what was written but it sounds like the IRMC.... Once the Fan relay goes there no replacement for it so i would wire it to a switch in the dash... so i would check the fan motor first then i wold go to the IRMC next then from there i would check the stupid sensor inside your water bottle near the air box! For some reason when mine went haywire and it shut my fan down for somereason to check that unplug the sensor int he water bottle... if you ahve ne other questions call me on my cell im pming you the number
 
cooling fan not working

I am still confused.
The 2 speeds on the fan work fine if hot wired.
I disconnected the coolant sensor, the fan still will not come on.(I replaced that sensor already)
I cut the #14 wire on the computer. The connector now shows about 12.5 v.
Great! right? But the fan won't come on . What is with that? I tried splicing into the ground and grounding to the battery ground. Still nothing.There must not be enough amps or something.
Are you saying there is a sensor in the coolant over flow bottle?
I only know of a low coolant sensor. Is that the one? I will try it any way.
If I cant find it I am ready to wire a new line direct to it.

Thanks
 
If the motor itself is running fine then it is not the coolant sensor.

If the fans will run if you hot wire them, but cutting wire 14 at the IRCM will not make anything work probably means the relays are shot inside the IRCM. You have 2 choices here.

1. Rebuild the IRCM. Some have done it by carefully opening up the case of the IRCM and soldering in new relays. A couple have actually wired in harnesses so the relays are external of the box so they can easily be replaced. I think there was a how-to in the members section at one time.

2. Get a hold of another IRCM.

Frit
 
I ended up wireing the low speed direct with a switch to ground and a fuseible link to the power distribution box.

It has been working fine so far, and the weather has been pretty hot.
thanks to every one
 
94/95 Cooling fan information

94/95 Main (puller) Fan Wiring Colors
Blue - Low Speed
Black/Orange - High Speed
Black - Ground

94/95 Auxillary (pusher) Fan Wiring
Blue - Low Speed
Black - Ground
White/Red - Low Speed (not used)

Early Model Fan Wiring Colors (for swap purposes)
Brown/Orange - Low Speed
Brown/Yellow - High Speed
Black - Ground

IRCM/CCRM Pin Outs (Main Fan Relays)
Pins 1/2 (black/yellow and black/orange) - Power to HIGH speed fan windings
Pins 6/7 (2 blue wires) - Power to LOW speed fan windings
Pin 13 (red) - 12V Ignition Hot (splice with 3A fuse if using external relays for fan)
Pin 14 (tan/orange) - Signal from EEC to IRCM for low speed fan
Pin 17 (green) - Signal from EEC to IRCM for high sped fan


Auxillary Fan Relay
Located on the DS fenderwell near the cowl/brake booster.
Red - 12V Key ON
Orange/Green - Trigger (ground to run fan at all times Key ON. Switch can be installed to open/close ground for manual control)
Yellow - Power from Power Distribution Box
Blue - Power to Fan

Power Distribution Block
Fuse (need to get ##) - 60A - Main Fan
Fuse (need to get ##) - 60A - Aux Fan

Testing Fans/Wiring
1. Check fuses!!! The main fan's 60A fuse likes to melt. I recommend running it off an external mega fuse and splice into the factory wiring.
2. Perform a KOEO Test. EEC will trigger low speed, high speed, then pusher fans to activate in sequence. Note what doesn't run.
3. Hotwire fan winding(s) that did not activate in KOEO test. If fan spins, you know it's most likely a relay or wiring.

Temp Solutions/Quick Fixes
Pusher Fan
1. Ground the trigger wire (Orange/Green) to run fan at all times Key ON. Switch can be installed to open/close ground for manual control.

Main Fan
1. Unplug the ECT (engine coolant temp) sensor. This will run the low speed fan at all times Key ON. It is located on the shaft that screws into the front, passenger side of the lower intake manifold. The passenger side heater core hose connects to this shaft directly beneath the ECT sensor.

2. Cut #14 wire in the IRCM to run low speed fan at all times Key ON. Switch can be installed to open/close circuit for manual control.

3. Splice #14 wire in IRCM to #17 to disable low speed windings (fan) when high-speed windings (fan) activate. This should be done if High Speed relay works in the IRCM and Low Speed is being run off a manual or thermo-electric switch. CAUTION - Running both windings at the same time will quickly burn out the fan and possibly cause a fire hazard/wires melting/additional electrical problems.

4. Splice the main fan's low speed fan wire (Blue) into the Blue power wire for the Auxillary fan. Ground the Aux fan relay as per above. This is best done only only when the IRCM or power to the main fan fails, but the fan motor itself is still functional.


IMPORTANT NOTE: EVTM manuals that state IRCM pin out 6/7 as the high speed fan windings are wrong. 6/7 (Blue wires) run to the low speed windings on the main puller fan. The black/yellow and black/orange of pin out 1/2 are for the high speed windings.

That is great info, anyone have this info for a 1990 SC? This would be fantastic info to have. I just installed a wire to run my fan on low when ignition on until I discover the problem. A good number of my other problems went away once I hot wired the fan. I really want to fix the cause though. This temp fix can't be good.
 
RF-22 vs RF-25

Hi. I am new to the forum and this is my first post.

This info is awesome. Thanks for putting it together.

I own a 1977 Bronco that has been designed as a rock crawler. I am researching electric fans and have come across information that a mid-90's SC electric fan may be what I am looking for as I am very restricted on space.

Can you please tell me the difference between the two electric fans available for the SC? The fordparts.com website it shows an RF-22 and an RF-25. I am trying to figure out which one is the 17" diameter fan that is about 3.75" deep.

My assumption is one is the radiator fan (puller) and the other may be a condensor fan (pusher) but I want to verify with the SCCoA experts first before I subject myself to a wild goose chase.

Thanks in advance.
 
I'm not finding squat on a search for Ford RF-25 on the web. I did find an RF-22 but it is just the fan motor, mind you it was a made in China replacement motor but that is all I could find.
 
Can you please tell me the difference between the two electric fans available for the SC? The fordparts.com website it shows an RF-22 and an RF-25. I am trying to figure out which one is the 17" diameter fan that is about 3.75" deep.

See http://www.ebay.com/itm/A-C-Condens...Parts_Accessories&hash=item4625769272&vxp=mtr -- it claims to be the 'condenser fan' and cross over to RF-25 & looks to be 3.75" deep?

If you keep going w/this, you may want to start your own thread so things don't get confused, etc. thanks.

Ken
 
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I'm not finding squat on a search for Ford RF-25 on the web. I did find an RF-22 but it is just the fan motor, mind you it was a made in China replacement motor but that is all I could find.

Les, I ran into the exact same issue; pretty strange. There is a plethora of information regarding Mark VIII and Taurus fans, but nada when it comes to the SC. I wish it were as simple as heading to a junkyard but SCs are hard to come by.
 
See http://www.ebay.com/itm/A-C-Condens...Parts_Accessories&hash=item4625769272&vxp=mtr -- it claims to be the 'condenser fan' and cross over to RF-25 & looks to be 3.75" deep?

If you keep going w/this, you may want to start your own thread so things don't get confused, etc. thanks.

Ken

Ken, thanks for the link. I am going to attempt to contact that seller to see if he can measure it for me. I will report my findings at the new thread I created for this issue.
http://www.sccoa.com/forums/showthr...identify-the-difference&p=1074380#post1074380

Thanks again.
 
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