just bought the truck with a bad motor, turned out it was the ac compressor clutch idler pulley seized, replaced the compressor, drier and orifice, evacuated system and charged, started up truck, compressor clutch pulled in for about 10 seconds and then disengaged, wouldn't come back on, shut off truck and started again, same thing, ran for 10 seconds and shut off, checked voltage at low and high pressure switches, I have 12 volts to both, running 12 volt at clutch for 10 seconds, then lose it, even though all the switches are closed with 12v at them. Is there something after the pressure controls that I am missing? Also, the CEL came on, scanned and have a p0351, checked the maintenance records since 16 miles on the truck and plugs have never been changed with 160,700 miles, guess I need to pull em and check all cop's. any advice on the ac is appreciated.

for all who has this problem, i found it, the #1 coil over plug was missing, installed new and checked the plugs and gap, everything works great now, runs smooth and perfect, ac works like it should. Must be limp mode decreases load on engine with misfire I don't know, sounds good to me

Glad you found it. A problem well explained is a problem half solved. It usally is something failrly simple that causes most problems. Thanks for posting back on it with the fix.