I've had issues with ac since I bought it. Compresor has been changed several times. Freon also.

Doesn't matter what the tempt is outside. Sometimes blows cold no issues. Most of the time, may not blow cold for 5-10 minutes. And it's not like its slowly getting colder. It is either working or its not.

Got to be Electrical?

 

Mostly a shot in the dark but possibly a mixing door issue?
It's easy to tell if the AC clutch is engaged, that would be where I'd start if you think it's a electrical issue. If the compressor is turning and it's charged it's making cold, just a matter of where it's going.

 

Sometimes the plug on the compressor can get dirty or corroded causing the compressor to not work sometimes. I know on my 7.3 trucks, it's real easy to see. My 6.4, the compressor is well hidden. To get to it you have to remove the passenger side inner wheel well.

 

Should be able to lift the hood and with the engine running turn the A/C on and hear a click as the compressor kicks in. Wonder if it is possible there is something not right in the dash controls?

 

Could be system has a leak, and the low pressure switch is not allowing the compressor to cut on

Have you put a set of gauges on it to see what kind of charge you have?


Also, a lot of people don't vacuum the system down before charging. You may not have a full charge

 

Subscribing.......

I brought up similar issues to you guys awhile back.....but where all the air was blowing out the defrost vents.

THAT got fixed (it blows where it's supposed to........)......a vacuum line.

But it's been doing what the OP describes. It'll blow cold as Hell for a few minutes......then it's get warmish. I can kick it back on by punching the accelerator for a few seconds. But obviously that only works in traffic conditions where I can punch the accelerator for a few seconds. Not a good idea if I'm in heavy traffic or right behind another vehicle........

2000 super duty PSD

 

Don't know about you citiots, but I have to clean the bugs and mud and grass out from between the condenser and radiator every three or four years to keep min working efficiently.

 

I'm pretty sure you saw the clean state of my engine compartment on my 'makeover' thread. Hell....Chris even commented on it.

 

And he doesn't even like you...

 

Ain't THAT the truth!

 

From another Ford Blog, I saw a chain on the identical problem. This is what the guy said fixed his. Unfortunately, that's a $1,300 part.

Just thought I'd repot. I finally got it fixed. It's been off and on last two years and I was convinced it was the thing behind the dash. Evaporator coil or whatever several people said it could be. Anyway it ended up being a bad pcm. It wasn't giving the signal to the AC to come on. I had my doubts when they told me that. I didn't want them throwing parts at it and that's first I'd ever heard anyone mention that as a potential problem. Well they were correct. It's working great. Finally!!! I'm amazed they had an 1157 bulb with wires soldered to it as their diagnostic lamp. Something about it having two filllaments to light up helped out. Them some hi-tech rednecks fosho

 

I try not to look under other dude's hoods if you know what I mean.

 

Steve, your truck is different than the OP's truck. READ THIS THREAD! https://www.fordtruckzone.com/threads/air-conditioning-issues.655300/
Also, I installed a ball valve in one of the heater hoses to shut off the water flowing through the heater core. Most A/C systems have a valve that does that automatically. Unfortunately our SD trucks don't have them. Some install a Ford Ranger valve and hook it up to work with the controls in the cab. I'm lazy, so I just cut a hose and installed a ball valve. When it gets hot, and I know it's going to stay hot, I pop the hood and turn the water off. When Fall comes around and I turn the heater on and I get cold air, I pop the hood and turn the water back on.