PCM fan control

builderpaul · April 1, 2005

Hi,

I am installing 05 fans on my 04 6.0. I don't want to spend $500 for a tune and I would rather not use the temp probe for control, I can get a plug in harness but will/can a dealer set up my pcm to control the fans?

Thanks

redvett · April 1, 2005

Hi,

I am installing 05 fans on my 04 6.0. I don't want to spend $500 for a tune and I would rather not use the temp probe for control, I can get a plug in harness but will/can a dealer set up my pcm to control the fans?

Thanks

<{POST_SNAPBACK}>

I just installed the OEM setup on my 04 1500 Silverado 4x4 ext. I used a thermo relay and a relay for the A/C and it works great. I have used the thermo units for years and never a problem. I am seeing a 2.3 mpg increase on a weekley trip of 250 mi. and its not even warm yet.

builderpaul · April 1, 2005

Hi,

I am installing 05 fans on my 04 6.0. I don't want to spend $500 for a tune and I would rather not use the temp probe for control, I can get a plug in harness but will/can a dealer set up my pcm to control the fans?

Thanks

<{POST_SNAPBACK}>

I just installed the OEM setup on my 04 1500 Silverado 4x4 ext. I used a thermo relay and a relay for the A/C and it works great. I have used the thermo units for years and never a problem. I am seeing a 2.3 mpg increase on a weekley trip of 250 mi. and its not even warm yet.

<{POST_SNAPBACK}>

Thanks for the replys.

Redvett where did you get your wireing stuff (probe and relay)?

Are the oem fans 2 speed?

Butch 02 Denali · April 1, 2005

I saw somewhere Paul that there was an electronic fan controller that would variable speed the fans based on temp. That would seem the perfect solution, was pricey though, about $125 or 150 as I remember. Anyone else seen that one?

redvett · April 1, 2005

The fans are not 2 speed they can be made to be variable but i chose not to. I used the 771-18905 controller to control 1 fan and a A/C relay with a diode on the A/C side so both fans run with the A/C . I have heard the Flex-lite varable controller has had fire related problems from the All Wheel Drive GM site.

The controller is from Jeg's

GM-Tech · April 1, 2005

I can get a plug in harness but will/can a dealer set up my pcm to control the fans?

No. We can't custom calibrate a PCM. We can only program it with the calibrations that are designed for it. Your truck didn't come with electric fans so there is no programming we can do to make it think it did.

Never really looked into it but the PCM for your '04 probably doesn't even have the circuitry necessary to control the fan relays.