oxfordgt

LOL that would have cost you about $250 to replace the ecu.

trance565

really? by passing the ecu would fry it? i wouldnt be sending any extra volts/amps to the ecu, woudla been a closed circuit with the can and switch, that's it.

oxfordgt

You would have been adding extra power to the system when you flipped that switch. By doing it the way I told you you are using the exsisting power that was already in the system and doing what the computer does anyway.

trance565

well, the computer doesnt like to turn the fan on alot of the time, and i just found out, even with teh switch, it doesnt like to turn it on sometimes.... about half the time. was working right after i put the switch in, get to school, wasnt working, get home, still aint working. i was doing this to solve that problem >.<

trance565

bump, any suggestions for the fan?

GolfmanSpeck

How is he adding extra power to the ECU when he had plans to disconnect the fan completely from the ECU to run his own switch?
As long as you disconnect the orignal red wire...(i'd disconnect the black too)... and run your own ground and positive wires, then you'll be fine. Make sure you use a relay rated up to 60A, otherwise you will fry switchs like crazy.

The orange wire is a signal wire back to the ECU. The ECU uses it just to measure whether the fan is spinning or it couldactually uses it to measure/control the fans RPMs. I am not sure which, I didn't design it. Either way I would disconnect it.

oxfordgt

If the computer isn't turning the fan on why didn't you just get a new temp sensor instead of going through all of this trouble.

trance565

cuz the sensor is fine, but the position is fubar and cant really be fixed, it's an 01 motor, so my brother had to use a t fitting to put both 98 sensor things on the one port the 01 motor had. and he stripped the plastic intake and jb welded it all in, so i dont really wanna take it off in case it doesnt go back.


i'de move it to a spot on the bottom of the block, but i cant see that wire stretching that far.

Dilireus

My ECU's programming got hosed by a chip and the high speed fan circuit hasn't work ever since. Everything else works fine, however. I just wired this up per Oxford's instructions and it works great. Thanks for posting this!

Racing2fast

Can I use this to turn my fan on with the car not running and just in Acc. mode? I was looking for a way to allow the fan to run after I turn the car off at the track, inbetween rounds, I want the fan to just run for a few min.'s help cool the coolant in the radiator, and move some air around the motor.

Can this work for that as well!

Tom