Cooling Fan

Yes it should Matt, once the car reaches operating temperature the fan "should" kick on. I thought you were concerned that it doesn't come on with the A/C......make up your mind, hehe :p

If it doesn't come on at all, but you've tested the fan by jumping it, you could have a bad "temp sensor". There are 2 on your car, one on each side of the "crossover tube"(black tube that goes around the alternator). One sensor sends a signal to the guage, and the other sends a signal to the ECU which in turn tells the VRCM to cycle the fan on/off. Not sure which is which, lol.
 
Matt94 said:
I also have a problem with my fan on my 94, but in my case it does not run at all, it has power to it. I hooked a wire to my positive battery and then to the green power wire on my fan and it ran fine. Would it possibly also be the VCRM?
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Matt94 said:
All of my fuses are ok. If I un hook the harness from the fan and test it with a voltmeter I get 12 volts. If I plug it back in and start the car I put the neg from my volt meter to the pos blue wire to my fan and the pos from my volt meter to the pos on my battery and I get 12 volts. I put my heat on high and still nothing and I put my a/c on high and still nothing, but my system has no 134a in it because my condenser has a hole in it, could this be a problem because my compressor isn’t running? Thanks
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Matt94 said:
...But shouldnt my fan run even when the a/c is off.
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According to the manual, the fan control will function with a bad ACP(Air Conditioning Pressure) sensor. I would surmise with zero pressure, the fan control would still function.

You stated the motor runs with power connected direct from the battery. That shows the motor is good.

I am only left with 2 scenarios...

1. The fan isn't being turned on by the VCRM because the coolant temperature never exceeds 215* - the point where the PCM signals the VCRM to turn on the fan OR the temperature sensor is at fault.

2. The VCRM is faulty.

You can check your actual cooling system temperature with an infra-red pyrometer. If the coolant temperature exceeds 215 degrees, the fan should come on providing the ECT(Engine Coolant Temperature) sensor is functioning properly.

Note: this is NOT the temperature gauge sending unit. The sending unit for the gauge has one wire going to it while the ECT sensor has a 2 wire harness connector. Both sensors are located on the crossover tube. The sending unit for the temperature gauge is on the drivers side while the ECT sensor is on the passenger side.

From the manual:

How The Circuit Works


The Cooling Fan System consists of a variable speed Cooling Fan Motor and a Variable Control Relay Module. The Variable Control Relay Module (VCRM) interfaces with the PCM to provide control of the cooling fan.

The Powertrain Control Module (PCM) monitors coolant temperature, vehicle speed, A/C head pressure, and A/C status to determine the speed at which the fan will operate. Once the fan speed is determined, the PCM signals the VCRM's fan output driver applying battery voltage from the Cool Fan Fuse to the windings of the Cooling Fan Motor.
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There is a whole barrage of test subroutines listed in the PowerTrain Diagnostic Routines for the VCRM and inter-related components.

Have you checked for any codes?
 
Sorry Driller.......lol, all that work and I posted before you. x) Now he has two confirmations of a good fan, and possible bad sensor. Great minds think alike :)
 
I have not checked for codes yet, and my fan will not turn on at all. My old motor has goten very hot and the fan did not kick on, my new motor has goten hot and still nothing. I think it wouldnt be the sendor because the fan has not turned on for two different motors. I belive it is the vcrm. At the least I put a switch on it.
 
Ahhhhhhh...

Pinpoint Tests

PINPOINT TEST B: ENGINE OVERHEATS


B6 CHECK COOLING FAN


~ Check temperature gauge at instrument cluster. Allow engine to RUN until high side of normal range is attained.

~ Check for cooling fan operation.

~ Did cooling fan operate OK?

Yes
GO to «Section 03-00» for Engine Service Procedure.

No
GO to Section 12-00, «Pinpoint Test F» for proper service procedure.

Pinpoint Tests

PINPOINT TEST F: MAGNETIC A/C CLUTCH DOES NOT DISENGAGE


F1 CHECK A/C CLUTCH OPERATION

~ Disconnect LH connector from EATC control assembly.

~ Does A/C clutch disengage?

Yes
REPLACE EATC control assembly.

No
CHECK for damaged, loose or corroded wiring, damaged variable control relay module (VCRM), powertrain control module (PCM) or shorted A/C cyclic switch.​
 
So you must have installed a used motor with used coolant temp sensors on it?

Starting to sound like a VCRM issue to me.....hit up a local junkyard and pull one for 10 bucks.
 
Thanks Driller I will do all of the tests, and yes a used motor. Is thier any other car that has the same VCRM as the Mark VIII? "town car, thunderbird" And also any other car that has the same fan, I know the thunderbird does.
 
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If your fan powers up I wouldn't even consider that as being bad(obviously). Honestly.....a quick fix would be to FIRST buy a coolant temp sensor(20 bucks maybe), swap it out(10 minutes tops) and see if that fixes it. Next would be to find a VCRM and swap that out....know anyone with a Mark 8? Borrow theirs and see if it fixes it :)
 
You are right that some model years of the T-bird fan crosses over(I forget exactly which ones), but I do not know any cross-over application on the VCRM.

For most of these modules, like J said, the best bet is to simply swap one from a working car.
 
I want another fan because I heard there kick a$$ and I want one for my fox body. I do not know anyone with another mark viii but Ill try the temp sensor and then proceed to a used VCRM if needed.
 
MAKE sure you run BIG power wires and a GOOD relay for the fan when you put it in the FOX. Been there done that :)
 
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