Exactly like the title asks, at what temperature does the low speed fan get triggered to come on? I've got my fan wired to just cut on full blast when the key is on. My factory low speed was dead when I got the car, my brand new fan lasted about a month before the low speed went out on it. Did not feel like pulling it out again just yet. I would like to run a temp switch to cut the fan on when needed.

What I did was went to a junk yard and cut the plugs off the car harness and the fan harness. Then flipped them around and pulled the appropriate pins out of the plug and pushed them back in so the constant 12v from the car harness is run to a relay then to the high speed wire on television fan side. The relay is triggered by the amp trigger on my after market stereo. So the fan runs high speed constantly when the key is on. This works fine and all but I don't want to burn up the fan so soon.

Plus I'd like to turn the car power on to mess with stuff or listen to the radio without the fan cutting on when the motor is off and cool.

 

Per the Bentley manual, and confirmed by my Scangauge, the fan operates at low speed at 221F, and turns off at 214F. The fan switches to high speed at 234F and remains on high until the coolant temps drops by 7F. Supposedly it also turns on when the AC is on and the AC system pressure reaches 8 bar (114psi)

 

Awesome, and I've been scratching my head on what to do about the ac being on. I might have to do a whole bunch of relays to trigger the fan based on the temp and the ac separately.

 

Try this thread. It solves the low speed fan issue that then allows the AC to operate. The relays are less than $10 on Amazon.

https://www.northamericanmotoring.co...-solution.html

 

That repair still requires taking everything off the front again to get at the correct wires on the fan to wire in the resistor. I'm trying to avoid pulling all that off again. If I'm going to do that I will buy a new fan with a better fan relay design.

 

What year is your car, 2 plugs or one? I did not have to remove the bumper and radiator. I tapped the harness next to the high pressure AC port.

 

02, so I've got the 2 plug with the relay built into the fan shroud. I'd have to remove the fan assembly to get to the relay to wire around it. You're lucky with an 07 and being able to skip that extra bit.