On a 2003 400i, i was told to run a wire from the acc in the fuse box to the switch then from the other terminal on the switch to the orange wire (spliced into) on the sensor and this will give me control of the fan, but it will still kick in when it needs to if i dont turn it on, i did this and it doesnt work?? what am i doing wrong?? I was told the sensor i need to tap into is the one closest to the outside of the block.

 

Help Please????

 

don't worry about sensors and fuses. look at the wires going into fan motor. pick one and splice a toggle switch (at least 20 amp) into it. it does not matter which wire you splice into as long as it is going into the fan motor.

 

My Cat is a bit older but I followed the directions as found on this forum from several weeks ago.

I simply spliced into both wires that go to the temp sensor that screws into the radiator and ran them to a switch. This allows you to turn the fan on at will while still allowing the fan to also turn on automatically as needed. This should also retain the protection of the fuse in the circuit.

For my installation I got a lighted switch (green, of course) that requires a third wire run for ground. Just make sure you mount the switch high enough you dont get it wet!

It was a simple installation and works great.

 

Ok so splice BOTH wires and run them to one side of the toggle switch?? The directions I saw were for a 500 and the wires are different colors. Catsmeow that will make it so I have to turn it off and on or will it still work by itself?? I just dont want to screw anything up so i want to make sure i know exactly what I am doing, thanks for all the help.

 

yes it will still come automatically if the toggle is in the on position

 

Hey doober the swithch you want is on the right side of the motor at the oil filter. You can tap into both wires and run to where the plastic housing is for the keys and stuff like that. Just use a simple on/off switch and turn it on when you want to.


Can I ask a Question why are you doing it??? I did it after the second switch went out.

 

Ya, doober, the 500 mod was mostly done at the rad where the sensor is. You have an oil cooler so you need to find the sensor for that and its the same. The colors will be a bit different on diff models. But you will need to tap into one side of the sensor to the switch and then down to the other side of the sensor. That should work? Let us know.

 

Got it figured , thanks for all the help people. KentuckyMartian, I am doing it because it seems to be running really hot, I asked my dealer if these engines are suppose to be running really hot and he said that they have talked to Cat and it wont hurt anything, but like any other engine, the cooler they are the better they run. my fan as it sits now doesnt come on very often, maybe 5 times in 230 miles?? ANd what really made me want to do it, was my last time out I just about boiled a pop that was in my bag that goes across my tank and hangs down by the engine.

 

Glad you got it figured out...great pics btw