I know some of the mid 80"s G and H engines had a 2 terminal radiator fan switch. I need to know if those 2 terminals are the switch legs and that the case is isolated from the switch. Meaning, there is no grounding to the chassis when the switch is either open or closed.

I replaced a clutch fan for and electric one.
I want to activate the relay by 12 supply, not grounding to chassis(as most 1 terminal switches do)
Thanks.

 

BBB,

The older OEM and many aftermarket thermostatic switches have both terminals isolated from ground. The AutoMeter switch on my TA fan is that way, and I just routed on of the terminals to ground to emulate an OEM sensor function:



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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Just so I get you clearly. The 85,86 G,H engine 2 terminal fan switch that comes up as the replacement part is an isolated unit?

Your did exactly what i'm going to do(right through the water outlet. Except i'm going 12v to switch to relay to ground. Looks like you went 12v to relay to switch to ground. Diff'rent strokes, diff'rent folks.

I can then (using a diode) hook my AC line to the relay also to activate the fan.

Thanks Vader.