Guys please don't attack me for posting this.. I've searched and search and haven't come up with nothin.. Here's my Dilemna, I'm from the toyota world and only know 2JZ and 1JZ supras and cressidas like the back of my hand..I don't know much about Mitsubishi's or how they're set up, I have my basic mechanical sense when dealing with anything out of the box.. But anyway, My girl has a 4G63T in her car and for some reason her cooling fans work whenever they feel like it. If the car is parked over night and i start it in the morning they will work fine going on and off as needed.. But once I start boosting the car they decide to stop working, causing the car to overheat.. So I decided to go over the wiring to see how it was wired up.. Long story short, I realized that the + side of the fan was the side linked to the fan switch which was odd to me because in toyotas we use the ground side to complete the circuit.. So what I did I completely re-wired the fans with new relays and wires and wired it as if i were wiring any other car with a fan switch.. So after i was finished I started the car to let it run to see if they would come on and they didn't.. while the car was running i cut the wire that was going to the fan switch and grounded it and the fans came on.. So that tells me that either there's a break in a wire somewhere or the fan switch is no good.. I went to my local parts store and they were telling me that the coolant temperature sensor is whats popping up in the system and not " fan switch.. I need to know where exactly is the fan switch located and does it matter if positive or negative current is needed to complete the circuit in order for the fans to operate.. Sorry for the long post but I want to get this right so that she can drive her car with no problems...

 

Also any pictures will be very helpful

 

Nobody has any information on this matter?

 

The coolant temp sensor is located near the outlet pipe on the top of the motor, drivers hand side toward the back of the car. The one in the front is for the gauge in the dash.

The fans are controlled by the cars ECU so if the temp sensor is bad it wont go on like it should.

 

Thanks, I got one today... I'm gonna change it tomorrow and see what happens.. What makes it kinda tricky is the fact that this engine is not in a evo its in another car in the mitsubishi family.. A friend of mine has a evo and in his car theres some kind of unit towards the front of the car of which my girlfriends car doesnt have.. I'm gonna change the sensor and see what happens

 

It will be differently setup on older 4g63's but the part is still around the same outlet pipe area AFAIK.

You'll have to work out which one controls the gauge and which one is the ecu's temp sender on your own.