I finally got around to picking up a low-temp switch from an '87-89 4.9L fuel rail & wiring it into the low-speed relay ground. It works - just as the thermostat opens, the fans come on.

I still have to find a hi-temp switch to trigger hi-speed, but I did add some wiring & switches to the dash so I can force the fans off, on hi (also with A/C), or leave them to run automatically.



See also:
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Owner caption April 2008 · Photo 2228 of 5000