Running an Aircon Complicates Matters even Further
A common mistake made by many D.I.Y. is to do all the correct wiring to cool the radiator, but forget the heat generated by the Aircon to the Condensor! If the Motor is still fairly cool, but the aircon is switched on (especially on a warm day) the temperatue in the condensor will rapidly increase and cause unnessesary strain on the aircon pump or might even blow a hose for that matter. Therefore a seperate relay should be connected from the Aircon pump to the fan wiring, or the wires from an aircon pressure switch can be used to switch the fan relay, else the fan will run continually while the Aircon is on. Overheating of the Condensor can be felt by running your hand accross it or on the outlet pipe from the Aircon Compressor to the Condensor. Just a thought.
The relay box is right on the side of the fuse box and you can see the large 30 amp fuse. I ran it to an adjustable temperature control there next to the shroud. And we used a heavy duty flex a lite finger chopper in the stock shroud. I even got a compliment on the install from the head tech at the lexus dealer. =) We intend to clean up the wiring and the heat sensor wire when it gets a little warmer but it's help for about 6 months with no issues at all. We even ran a on off to the relay into the cabin so he could manually shut off the fan if needed. The switch is also ran into an acc line so the fans wont run when the car is shut off. Also the air-conditioner hasn't given him any heat issues yet. This is probably because the heat probe goes through the radiator into the condenser as well. So heat from either the condenser or the radiator can turn the fan on itself.
