Can i use the coolant sensor mounted on thermostat housing on the D16Z with the wire harness from my 91 Si? does it matter which way i hook up the two wires to it?

 

You talking about the fan switch right?

Just rewire to the new switch on the thermo housing.
Don't matter which way you wire it.

 

yeah,the big one right above the oil filter,next to oil pressure switch on D16A...its not threaded for sensor,casted closed on my D16Z,needs to be drilled and tapped,but i dont want to risk it cause short block is built and it would really suck if i screwed up the block trying to tap and thread it....anyway,thanks! good to know it will work on the smaller sensor on thermostat housing.