hey i have a 2004 f-150 with 4.6l. I'm trying to wire up my electric fans to turn on with the a/c. what wire are you guys using for a signal?

The grey/white wire in front of pcm only has a signal when the compresser kicks on. so then the fans would only be on with the compresser. I want the Fans to be on all the time with the A/C switch light on.

Also what temp senders are you using?

 

Sounds like the one I've got mine tied into, but it does cycle with the compressor. I'm using the radiator probes that came with the controllers.

 

how well does the a/c work like that? still blows cold while truck is stopped?

 

The idea is the fans are on when the compressor is on. Makes no sense to have them pulling low pressure when the A/C isnt even being cycled through the condenser

 

well the reason the fans need to be on all the time is when your a/c compresser is on the temp of the refrigerant drops which lowers the the pressure of it. your low pressure switch cuts the power to your compresser to prevent freeze up.

So if your fans only on when the compresser is on, your a/c compresser will not cycle as fast. So then your not going to have as cold of duct temps.

 

I live in south Louisiana, and my a/c works just fine. When the a/c is not cycling, there's no need to draw air through the condenser. Think about how your home unit works.

 

Get a controller that uses the temp probe and the AC. Mine turns the fans on at 50% when the AC is on. Otherwise it only comes on when it gets hot enough.