i am patiently waiting for this cuz i hate traffic heat !I see a need for such a switch so one can turn ON the fan manually. Will help delay temps going up when sitting stopped in traffic.
I have a schematic drawed up and will post it over the weekend along with pictures. So this is a thread that is "work in progress".
Fan over ride switches are nothing new. I'm just posting how I did it. Basically here is how it works.
The fan is turned on and off by a relay. The relay closes when the water temperature reaches 205'.
The relay coil gets it positive directly from the ignition switch and its ground from its ECU. So basically the ECU switches the negative to the fan relay on and off to turn on the fan at 205, and back off at 194.
So basically any SPST switch will work. One side of the switch goes to any chassis ground and the other taps into one wire coming out of the ECU using a posi tap splice so no wire has to be cut. Then when the switch is turned on, the wire coming out of the ECU is grounded and thus the fan turns on. Turning off the switch puts the system back to stock.
So basically you need to know which wire to tap into and I disclose that wire color on my schematic.
More to come.
No problem, I posted the link to give members an Idea what is involved. If you give a good "How To" for the 3rd Gen I will stick it permanently like the 1st Gen "how to"That's not how I did it. That requires tapping into 2 wires at the ECU. My scheme only taps into 1 wire at the ECU and the color of the wire at the ECU I used is different than the post you quoted. That is an 04/05 ECU and the wiring and ECU for the 08/09 is some different.
This thread is only how I did it for the 08/09's. My scheme is not applicable for the other Gen's.