My '02 received an M20 conversion two owners ago, and I've had a few minor things to sort out. Since I got the car a few months ago the electric pusher fan always came on with the ignition and I thought it must have just been wired that way. Yesterday I noticed that it wasn't coming on at all, and the temp did climb past it's usual position (parked at 180F on the aftermarket gage). I know next to nothing about electrics, but I did poke around and determine that there's a relay (top right of the photo) which had switched power, and a thermo switch on the aluminum radiator. After cleaning the spade contact on the switch and some wiggling, the fan did come on with the ignition. It also comes on if I touch the wire to the radiator. The switch appears to have failed closed, at least most of the time. It also appears to have teflon tape on the threads, which doesn't seem like a good idea, unless the coolant is enough of a ground.
I'm trying to determine if the switch is something I can just pick up at NAPA before I drain the radiator. It's located next to the hose at the thermostat outlet (I assume). There's also a radiator hose at the same side on the top (the return?). The rad cap drains to the ground (no overflow tank), if that matters.
Would it be easy to get a matching part without pulling this one? Does a 91C switch sound good here? What should I use on the threads? Any other tips? Thanks!