22RE temperature Switch

[docj88]

I need a 190 degree coolant temp switch to ground an E-fan relay. I know there are 3 different coolant sensors on a '88 22RE. I'm hoping that one of them will do what I want it to. If not, I'm going to TIG a bung into the thermostat housing. If I do go with a bung, what material is the housing made from? Cast steel would be ideal, cast iron would be.. not fun. Aluminum would be fairly simple as well, but I need to know if I need a steel or aluminum bung. I think it's aluminum but I'm probably wrong.

 

[Rbx]

I used a thermal temp switch shoved in the radiator fan. Not a fan of this method but I couldn’t figure out which switch on the engine would give me the temp I wanted the fan to turn on.