I've been trying to figure out whats been causing my truck to stumble once its warmed up (1992 C2500 350 TBI 160k+ miles) somehow managed to get it to run properly again after unhooking the PCV valve and reattaching it (and yes it i did the rattle test and it was fine) but i digress the issue i am having now is on my temperature control for my vents and such my A/C light has started to flash when i start my truck up it will do that for about 5-10 minutes then go away, also it will do it if i try to use the A/C, i've had it nearly a year only used the A/C twice, any recomendations would be nice, dont realy need ac where i live.