Hi everyone,

I have my 2004 crossfire fans running full speed about 20 seconds after starting the engine.
When I unplug the fan control module it stops.
Does come from the fan control module or the temperature sensor?

Thank you

 

You are in Tahiti? Is that the only Crossfire on the island?
Is the A/C turned on?
If you have the A/C turned on I would expect the fan to go to full speed.
Does it ever go back down or turn itself off?

 

Yes Iīm in Tahiti.
There are less than 10 crossfire in Tahiti but I sa only 2 others on the road. Sometimes other owners come to me to offer to buy theirs.
Mine is the only one that is not stock. I made some customizations.
A/C ON or OFF thatīs change the running speed. It run fait from start to stop.
Iīve recently change my RCM for no start problems. But fan speed was normal.

 

I'm not an electronic tech, but what I would try is to pull fuse 33 and 35 in the under hood fuse box. Fuse 33 and 35 powers part of the A/C control module.
Turn the ignition switch to the 3 position; do not start the car. Does your radiator fan go to full speed?
Yes, it goes fast, then I think the Fan Control Module is bad.
No, the fan does not go fast, Then I think the high speed is being caused by the A/C control module.

The fan control module has two wires going to the fan motor and a brown ground wire. The BK wire comes with power from a 50 amp fuse in the engine fuse block,
It also gets power from the ignition switch when turned to the 3 position.(PK/RD wire)
The gray wire connects with the Power Train Control Module (PTCM) which is the brain controlling the fan.

Fuses 15, 33, 34, 35,36 and 37 all supply power to the A/C control module. That should be true here in the USA, Export cars may be a little different.
I'm thinking that taking away power from the A/C module will prohibit it from controlling the fan speed. By taking the A/C module out of the picture then it can only be the fan control module or the PTCM that is bad. PTCM seldom have problems and the car is running OK, so let us assume the PTCM is good. THING IS THAT REASONING COULD BE IN ERROR AS THE PTCM MAY BE PROGRAMED TO RUN THE FAN FULL SPEED IF IT DOESN'T GET ANY INFO FROM THE A/C MODULE. I just don't know. Try it with the car engine running also.

From you "A/C ON or OFF thatīs change the running speed. It run fait from start to stop."

If you have continuity on the gray wire between the PTCM and the Fan Control Module then the problem is most likely in the Fan Control module and it should be replaced.

Are any warning lights on? The radiator light or the check engine light?

GOOD LUCK! & WELCOME TO THE FORUM!
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