Fan runs all of the time?

Ronald Wendt

Registered User
Mine does and I figured whoever had the car before me did the wiring trick to make it so.

While changing out the fan today I decided to take a look. I disconnected the wiring harness from the module. I see the numbers, but when I trace the wires back to the fan, I can see no modifications. I could not see where anything had been done to the module either.

Since I am not clear on what exactly you do for this mod, what should I look for?

If the wiring has not been changed, what else could cause the fan to run all of the time?

Any help will be most appreciated

Ron
 
Hey Ronald Wendt

First thing I would do is pull codes. To see if any other problems are causing your fan to run all the time maybe you have a bad ECT sensor These cars will contine to work with bad sensors they go it to what is called FMEM failure mode effects management this is a condition where the EEC blocks a bad sensor and runs a baseline to keep the car going it is a longshot but worth trying it does read as if sombody has hotwired your fan .... My fan never turns on my car runs so cool it is never used the only time the fan comes on is during the KOEO test so I now it is working proper but just isn't need at this time in the life of this engine..
 
The mod you are talking about includes cutting the control wire from the EEC to the IRCM. It is a small (18 gauge) tan/orange wire in the big fat harness going to the IRCM.
 
Well as it so happens, the check engine light has been on since I bought the car. It always has run fine and everything seems to work, so I have just never gotten around to have the codes read if any. The car did hit a deer in its former life, passenger front corner.

I will certainly get the codes read real soon, maybe I can find out whats going on

Thanks

Ron
 
Behind the front passenger headlight rests the integrated relay control module (IRCM). This device includes the relays that operate the low and high speed fan. Its possible the impact with the deer damaged it.

Its also possible that the ECT sensor is either not functioning correctly, has a short in the wiring harness, or is simply not plugged in. Unplugging it would have the effect of making the ECM engauge the high speed fan constantly as a safety against a possibly overheating engine.

The ECT sensor is a small sensor in front of the supercharger, near (on?) the thermostat housing. I replaced mine last year, don't remember its exact location now but you should be able to find it readily.

Hope that helps..
 
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