Coolent fan not operational

[352Ford2]

All right, on my 94 cobra the rad fan decided to quit working recently, so she likes to overheat. I checked the stupid simple stuff (mega fuse under the hood, and replaced the engine coolant temp sensor).

Before I start actually diagnosing it, is their any other stupid simple stuff off the top of your guys heads I should check (hidden fusible links, relay, etc.)?

One last thing, the fan does turn on when I turn on the AC, so the fan oviously works.

 

[The Green GT]

Check your VIN on Fords website. There was/is a recall on a part of our fans.

 

[352Ford2]

hmmmm, according to here there are no re-calls on my car, but it also lists my cobra as a GT, very odd...

http://www.ford.com/en/vehicles/owners/recalls/default.htm#ford

 

[fordtech28]

My cobra did the same thing to me 4 years ago it would only turn on with the AC.Did you try unplugging the coolant temp sensor sensor to see if the fan turns onif it doesnt in my case the low speed relay in the ccrm box burned out.I just put a aftermarket fan controller or else I had to replace the whole ccrm box which is not cheap just to get the low speed fan to turn on problem solved

 

[HISSIN50]

You might find something helpful (or not ) here.



Here's an excerpt from another tech note:



The stock 94-95 GT fan is a two speed unit. Low speed comes on at ~208*F. High speed comes on at ~228*F. To check if the appropriate fan is being triggered by the computer: To check low speed fan operation, look for 12 volts at CCRM pin 14 with ECT temps greater than ~208*F To check high speed fan triggering, look for continuity to ground at CCRM Pin 17.

Please see here for further CCRM diagnostics.

There is a fuse for the fan in the underhood fuse box so don’t forget to check it. There is also an EDF fuse. Don’t forget about it either.

-If the car cools decently while going slow for a bit but then heats up until shut off and restarted later (where this cycle repeats), check to see if a circuit breaker was installed on the fan harness. When thermal thresholds are reached, the breaker opens, turning the fan off.

The fan connector/interface itself was known for heating excessively. Unclip the fan connector from the fan motor and ensure that the connector itself and wires and terminals don’t show signs of overheating. Often times, this is overtly evident. Some cars have a circuit breaker retrofitted to the fan connector. If it seems like the fan stops working after a bit of operation, see if this breaker has opened the circuit. This has been known to occur (the breaker was an attempt to keep fan motors/wiring from overloading and catching on fire).

Many desire to install switches to control the fan speeds manually. One would connect CCRM Pin 14 to twelve volts via a switch for low speed switching. One would connect CCRM Pin 17 to ground via a switch for high speed fan operation. Do not run both speeds at once (either via the switches or accidental clashing of one fan switch and the OEM control). A write-up for this modification exists here

If you should decide to do away with the OEM fan control, which many do as it leaves quite a bit to be desired, a soft start or variable fan controller is a popular and wise option. Flexalite, SPAL and Dc Control all offer such controllers. This user chooses to use a Dc Controller (www.DcControl.com). It uses pulsewidth modulation to provide infinitely variable fan control. I have used the controller in 115*F ambient temps while stuck in traffic and the unit excels.




Do you know if you lost high and low speed or just one or the other?


Good luck.