My truck is tuned and the AC works just fine.

 

Just dropped the stock tune back on... No change. A/c blows cold at idle, but as soon as RPM's go up, she gets warm again.

Think it may need a recharge?

 

Get one with a gauge, if freon is still in there you can recharge it. Lot's of info in here but do a search.

 

Update:

I did not find the can of R-134, BUT, I did find the removable gauge attachment that came with it.

Started the truck, cranked the a/c on, cycled it a few times, and left it on for a few minutes. Popped the gauge on the low-side, and was sitting pretty close to 40 PSI - which according to the gauge - is acceptable.

Any other ideas?

 

You can't just put the gauge on it and know if the system is working properly. Put a proper line set on it and see how both the high side and low side look.

 

Pressures are dependant on abient temps. and humidity. There are charts for the proper charging of an AC system if your not evacuating and charging from scratch by volume. Having a hi and low side gauge also lets you know if there's a blockage such as in the orifice tube.

 

Thanks. Looks like we will have to wait a bit before diving into this issue. Doing all the other major work has quite literally drained us.

Was hoping it was something simple I could tackle with tools I already have - unfortunately a full gauge set is not one of those things, so for right now, I'm trying to rule out items that do not require a gauge set.
Air Gap on the compressor is about .035. Spec calls for ~.020. Is this possibly the issue? Increased RPM and the thing 'releases?'

Hard to troubleshoot with only two hands. Am going to have wife bring the revs up while I'm watching the a/c compressor to see if it is actually dropping out or not. Truck is too loud to hear if the compressor is dropping out.





A quick recap of what I know so far about the a/c system.

Works AWESOME at idle. Both the Front and Rear air blow very cold.
Seems like anything above 1000rpm and you can tell pretty quick that the air conditioner is no longer uhhh... 'conditioning.'

Only had a low-side gauge, and that reads around 40psi at idle with the a/c blowing cold.

Air-gap is .035.

Thanks for the help and suggestion on gauges. Have got calls out to a few friends to see if they have full gauge sets.

 

Wierd. Wanted to make sure plugs were all tight. Started with the low pressure switch. Unplugged, blew a little compressed air in the female plug, pushed it back together and went for a drive. Would you believe that the a/c frickin blew cold from that point forward?!

Kind of a crappy place for the plug/sensor... Right below the metal lines that sweat bad.

All is well in the world again. Was 94 outside here today!

 

Glad you got it fixed...doesn't it give you a warm fuzzy feeling when a plan comes together and the air out of the vents is 38 degrees?...........;-)

 

If by 'warm fuzzy feeling' you mean 'happy that my wife wont have a stroke' feeling - then yes... I got a warm fuzzy! haha

 

Congrats on the find. Doesn't it make you feel good when you fix something by accident. Good thing you didn't try to add more freon. Now you know why you need gauges. More freon could have locked up your AC compressor for good.

 

Just wanted to give a laaaaaate bump with an update 6 months post all the work.

This Excursion ROCKS. Have had ZERO issues since June (the a/c thing - apparently on the 03 Excursions, writing a fresh tune overwrites something and the a/c compressor acts funny for 15-20 miles.)