Today I bought an engine out of a 90 gxl to put in my 89 gtu. I was looking it over tonight to see if there were any vacuum lines that needed to be replaced, whether or not the 5th and 6th ports are stuck(they are), or if any connections that needed to be fixed and I ran across this...



This is the back ofthe water pump on the 90gxl engine... why is the sensor that should be below the green sensor missing (the one that the circled connector goes to)? Was that a change from 89 to 90 that mazda made? What is the sensor for? (extra temp sensor or something else?)

This is a pump from an 89 Gxl and it has the sensor... so does the pump that was in my 89 gtu.



Should I switch pumps or will I not need the extra sensor for my 89 gtu? Or should I just run the computer from the 90 and not change the pump?

Thanks for the help,
Rob

 

The extra sensor is a temp switch for the auxiliary electric fan fitted to some FC's. I believe all turbos and autos had it, and it was optional on others. It runs if the A/C is on or if the coolant reaches 207degF (that's what the temp switch is for).

If the car didn't have the fan then it didn't have the switch either. If your car has the fan (it's in front of the A/C condensor) then fit the pump housing with the switch in it.

 

Thanks for the info, I'll check on that today.