I know it’s been awhile, but I have been working on the truck. When it got really hot, 102F, the A/C sucks, and the engine got hot at red lights. I’ve heard this about these trucks from a few forums. I started to investigate.
1st off, the fan shroud was chopped. The previous owner and his redneck ingenuity, removed the bottom section of the fan shroud to replace the water pump, with out removing the fan. Needless to say the fan did not pull air correctly at idle. I replaced it.
I also added a helper fan to push air through the condenser:
I don’t think it really does 2500 CFM as advertised, but the price and size was right. I even though I only needed 30 amp relays, I found a great deal for 5 70 amp relays and harnesses for only 15 $$! Here’s a picture of the relay tapped into the fuel pump hot wire ( the fan relay clicks on when the fuel pump comes on, with the key turned in the ignition)The biggest improvement I made was the foil duct tape to seal the air gaps between the radiator and condenser. This ensures that the air is pulled through the condenser and then the radiator. Now that it’s all done, the engine doesn’t run hot sitting at stop lights, the A/C runs great at 98 degrees and below. There seems to still be a knee curve on the A/C performance above 98 degrees F, where the thing works as hard a s possible, but can’t remove and more energy from the air. I’ll check the 143a coolant levels in the coming weeks and see if there’s a problem, but the system might have reached its limit.Thanks for reading.