The 3.1L is from a 91 Firebird. This has a single green wire connector that is at front left corner of the driverside head. I've read on the forum and in my haynes manual (diagram for an 87 2.8L) that the radiator fan switch is located at the rear of the passenger side head but I've searched to no avail. I saw another post where someone else with a 3.1 could not find it either. The connector in the pic doesn't look like a fan switch connector but I'm still curious as to what this sensor/switch can be. Thanks in advance.

 

coolant temp sensor

 

That sensor is the coolant temperature for the dash gauge (single green wire). On the front/top drivers side of the intake manifold is the coolant temperature sensor for the ECM (2 wires). The fan on the 3.1 is ECM controlled, with additional control via the A/C high pressure switch. No fan switch in pass head on the 3.1's.

RBob.

 

IS THIS
Same thing &
Same location for
1985?
THANK YOU

 

Should be. My '87 is the same.