fan switch not triggering fan

[FireFight]

Hey guys, Im now driving my swapped car, now I'm getting the small things out of the way.
One thing that is bugging me is that the factory fan switch isn't triggering the fan to come one

Set up:
New 318i(m42) radiator
New early style 318I(m10) fan switch
Misimoto fan
Bosch relay


If I unplug the wires from the switch and touch them the fan kicks on, so clearly its not sending signal though the posts.

So I'm thinking the only reason this could be happening would be its low on coolant and the fan switch isn't heating up, but i have the radiator filled.

thanks

[e30davie]

My suggestion is to remove fan switch, connect multi meter and dump it in a cup of boiling water to see if it switch works as you expect it.

maybe it just never gets hot enough to switch the fan on? if you let it idle for ages and watch the engine temp rise on the gauge does it look like its going to overheat from the fan not switching on?

[FireFight]

maybe it just never gets hot enough to switch the fan on? if you let it idle for ages and watch the engine temp rise on the gauge does it look like its going to overheat from the fan not switching on?

OHH Yeah, in traffic, it almost hit red on the temp gauge, i pulled over and bypassed the switch to get home.

Ill try pulling it and boiling it

[ADEN]

check temp switch connector for loose or corrosion.mine was doing the same.also low coolent does this.