I installed a Compressor Works 16" electric fan and a hayden 3647 fan controller from Oreillys a few months ago.I hooked it up to the ac compressor so it will come on with the ac compressor.I noticed the other day when I started the truck to warm it up that if i have the heat on defrost when the truck is cold the electric fan kicks on and off repeatedly.It will kick on and shut off after about a second or two.Then about 10 seconds later it will do it again.Over and over.But if the truck is at operating temp it doesn't do it.And it wont do it if I put the heat on the vents.

 

When you set your vents to defrost, it automatically enables the a/c compressor. Refrigerated air carries less moisture. (although, during the winter, ALL of the air is refrigerated in any event.....) Sounds like your a/c system may be low on charge.

 

I don't have mine associated with my A/C at all. There is already an electric fan on my A/C compressor. Mine is simply operated via the temp probe stuck in my radiator...

 

Hammer, yours and mine have separate exchanges.. theirs have one unit that share..

OP- I would rec you DO disassociate your a/c from the cooling system- as Hammer indicates.. OR, I would rec you introduce another e-fan that toggles with the same switch from your controller.. you can run directly to the battery for power, but make certain it is fused and relayed.. POOF- problem gone..

one of the things that can cause you grief is that the e-fan, while the condenser is operating, will run the cooling fan before the engine reaches operating temperature, which will cause you to run cooler than you're going to want (p1281)... It likely won't happen in the summer, but it absolutely can in the winter..

 

Yeah I think I will disconnect it from the compressor.I dont like how it kicks on and off like that.Thanks guys.