ok so i am sure that the clutch is going out gonna get a new one this week

? is can i put a switch on it to engage fan like a big truck can you tie into 1 of the wires with either a hot or a ground and make it come on

reason i ask is i idle truck sometimes 12 hrs a day ac needs all the help it can get

heard my buddies 6.7 yesterday while idiling and the fan clutch was kiking in and out like a big truck

on a big truck you kick the fan on and it helps keep the high side pressure down and therefore ac stays colder while idiling

 

First try just adding some refrigerant to your a/c system. My truck has done the same thing and once I top it off with refrigerant, it works fine at idle. I find it needs topping off about every 2 years.

 

It could be the fan clutch, but I have found that the computer really doesn't turn the fan on until high side pressure gets way out of check anyway. That can lead to freon escaping from the relief and over a period of time you end up with a low charge.

To answer your question I don't know of a way to manually control the fan without setting codes and the check engine light. Some people mount a thermostat controlled fan on the condenser to alleviate the problem I stated above. One could also be wired in off a relay to run when the compressor is engaged so that you don't have to fool with a thermostat.

 

here's the schematic showing the wireing for my fan on my 03 so if you want to poke and play, you might see if this is like yours.

I put a small diode inline with the wiring and used the spare relay to turn mine on and off manually. The diode prevents the computer from seeing a back flowing voltage signal when it thinks it shouldn't.