I have a 91 f 150. it has been converted from r12 to r134a xh7 kit. The air is not cold at all even fully charged with refrigerant. I have access to r12. should i convert it back to r12 or can i use the existing setup? would r12 be any colder? any feedback greatly appreciated.

 

I converted my 91 F150 to R134a 14 months ago using one of those $50 kits and it's still blowing plenty cold today. If yours is not, then it may be something other than the refrigerant is wrong and converting back to R12 wouldn't do anything for you other than cost a lot of money. YMMV.

 

Robert has a valid point. R-134a conversions do not work as well as the original R-12 but the vent temperatures should still be in the mid to high 40s on your truck. You really need a manifold gauge set to see what is going on. Your condenser could be plugged, poor airflow due to a faulty fan clutch or perhaps the fan shroud is also missing?

Let's hope you are not in the early stages of Black Death