Fan problem

R

Robertf

Registered
The fan on my Mark comes on when I turn on the the ignition and remains on while the car is running. I tried disconnecting both the coolant temp sensors but that doesn't stop the fan. Is this a VRCM problem?
 
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Is the MAX AC on?
 
The AC clutch doesn't engage when the AC is turned on but the fan runs whether the AC is turned on or not.
 
Sounds like it is more of an AC problem? The VCRM interlinks the AC and fan function. Something in the AC system may be malfunctioning thus commanding the fan on? I know I'm not much help, but I don't really know much about the AC system.
 
Well, this is probably no help whatsoever, but since there's nothing definite here yet: I had the opposite problem, quite a few times with my fan not turning on at all. It was a connection, and on the way to Carlisle, Hubby had to solder the connection so the fan would stay on at all times. Honestly, I don't see how this would help you at all except to say take a look at the connection?
 
Since it's running as soon as you turn the key to on, i would say that you have a VLCM issue. The module is powered on electrically, but controlled by the main pcm. It sends a signal via the databus (SCP language) to the module, to turn on the fan. It should never run with the key on and engine off. Unless of course your main pcm has a problem. But, I don't think that its likely. Especially since the A/C clutch doesn't engage, when you select A/C.
 
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Thanks for all the help. I'll pull the VLCM and check the wiring. From what I've read, the 96 VLCM doesn't interchange with the other year cars. Is that true?
 
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Robertf said:
Thanks for all the help. I'll pull the VLCM and check the wiring. From what I've read, the 96 VLCM doesn't interchange with the other year cars. Is that true?
Click to expand...

Sad but true.
 
There really is no wiring to check. You can't read the databus, and the relay is inside the module. Power goes into the vlcm, to the relay and sits there. When that relay is turned on, power then goes thru the PWM circuitry. Then back out to the fan. Which by the way is only on 1 wire. The other positive wire in the harness, dead ends just about where the frame rail is.
You can go to autozone and have them check your vehicle for codes. VLCM codes start with a U.
 
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