I have an 06 5.4L XLT
Apologies if this is discussed often but I have a pretty weak ac and have heard that there is often issues with them.
The AC will sometimes blow cold, either when going down the road or if I keep the RPMs higher than idle, maybe 2.5-3k it will blow at least somewhat cold.
I have check the refrigerant about a year ago and it looked alright but I only used on of the little gauges that comes on a can of refrigerant.
I can hear the condenser cut on and its obviously blowing cold some of the time.

Is there any common fixes for this/things to check? Thanks for any help!

 

Welcome.

 

Low charge. Check refrigerant charge with gauges to see the H/L side readings.

 

Seconded. Here's an article that might help: Car AC blows warm at idle — Ricks Free Auto Repair Advice Ricks Free Auto Repair Advice | Automotive Repair Tips and How-To

 

Low refrigerant charge would not be expected to cause "intermittent" AC operation, it would usually manifest as "poor (or no) AC system performance. It is important to accurately characterize the situation.

A/C operation that is truly intermittent on older F150s is usually caused by a worn compressor clutch causing an excessive gap.

 

Low charge would result in colder air at higher RPM's as the pressure builds, and as you say, It is important to accurately characterize the situation, so why not start with a basic test, then go forward, rather than looking into a compressor replacement as the diagnosis?

 

Check the gap in the clutch. Remove shims as necessary