2001 Yukon ac blow warm at idle but cold at speed

[Dvdtactical]

2001 Yukon 5.3 4x4 SLT with rear air and manual controls.

Pressures are at spec. Replaced compressor, R drier, o tube, lines as needed. At start up it blows COLD 36-40F. Head out it blows cold. Stop at store 25 minutes away and it blows really warm. Pressure on low side runs 45-50. Drive home and it blows cold again. Park and idle it stays blowing cold. Guess the truck doesn't like going to town.

 

[Scottydoggs]

the fans coming on?

 

[Fless]

If the electric fan mod hasn't been done, is the fan clutch working correctly?

Are both halves of the fan shroud in place?