OK, I have a 99 sierra that I would like to swap the clutch fan and small radiator with a 2005 that has the 34" and elec fans. I know I will need a Nelson harness and the 99 will have to be tuned to control them.

My real question is will the 2005 have to be reprogramed so that a check engine light does not come on? Will the computer notice that there is nothing plugged into the fan control harness and throw a code???

 

I think you would have to repgram it. Or disable both of those pins.

Are you putting the clutch fan on the 05?

 

got a 2005 rental truck eh?

 

heheh sounds like a plan batman

 

Yes, the check engine light will come on in the 05 truck. and hp tuners can disable it but it will turn on again.

 

Sorry guys I've been away from internet for a few days. I appreciate the info. Wasn't really planning on a rental truck, although...........anyway back to my question.

Demon: Yes the clutch fan will be going on the 05.

graysilerado5.3: So even though you disable the MIL with hp it will still comeback on in a few days? Does the computer try to relearn factory parameters or something? I don't understand that. I'm not doubting you, it just doesn't make sense.