Hey guys,

My A.C. works rather well but it will only work on the highest blowing setting. What do you think the issue is?

 

Does it barely come out of the vents any other setting?

 

nothing on the other settings?

 

A ha, classic. You need to clean your evaporator core. I don't know of any write-up on it. You need to unbolt the black ac box under your dash, there's a few under the dash inside the cab that also need to be unbolted. Anyways, unbolt it and pull it outta there then get in there with a garden hose and spray all the contents of that out. There's gonna be alot of whole leaves, rotted leaves, and other debris in there so take your time and be thorough. My truck damn near blows iceicles at me after I did it. Also, spray out the evaporator core real good, it'll be kinda like using a hose to spray mud out of a radiator to unclog it.

 

Is there a box under the hood or is this stuff all inside the cab?

 

http://media.photobucket.com/image/F...corebefore.jpg

 

I have no idea where to even start? I have zero experience. Do you think I should just have a mechanic do it

 

You could, if they have any idea what I'm talking about.

 

Is this just on the A/C? Or same symptoms on heat, vent, etc.? If it's on all temp controls, before you get too carried away, on the front of the blower motor housing (in the engine bay where you'll need to open up to access the evap core), there is a wiring connector plugged into the blower motor resistor.

I would honestly try replacing that resistor before going any further. For $15, you don't stand to lose much, and it's a common failure. You can get one online or at any local parts store. Usually when these go, you end up with your high setting running as normal, but no flow on any other setting because the fan is built to run on high without the resistor, and the resistor reduces voltage to the fan for your other settings.