Hi, I have a 2000 RamVan 3500 recently changed the radiator fan to an electric on, did notice a difference but it turns on at all speeds if the air conditioner is on, due to the speed and wind you dont need it over a certain MPH.

I know the cruise control wont come on below a certain speed and to save electricity I want to do the same, does anyone know if there is a wire I can hook into to enable the fan and only slow speeds..?

thanks,
david roesch

 

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Either use the OD wire to trip a relay to interrupt the fan relay power, or install a temperature probe at the A/C condenser that will interrupt the A/C trip wire.

 

Thanks.. Not sure why I didnt think of the overdrive, since I already hooked into reverse when I added a backup camera(ClassB-RV on Dodge Chassis).

Maybe I'm wrong but I dont think the fan will help driving over 40mph, with both fans burning 60amps, could be saved to charge both batteries(coach / engine).

 

Yep, you're wrong, the tipping point is 35 MPH not 40.