I installed a Vintage A/C package in my 3100. My problem is when I go down the road 40-50 mph, the air gets warm. When I slow down it cools back down. I charge by the sight glass. It gets cold and it is not freezing up. Every thing is fine when Im parked. My temp on the radiator stays the same. My truck basically has always run cool. I have a 292 motor, an electric pull fan that sits high on my radiator. So its not low enough to pull the evaporator coil completely, the condenser sits lower in front of my radiator. I have been doing A/C work nearly 40 years. So, either the charge isnt right or i need a push fan in front of the condenser coil. Also, Im running around 30-40 psi on the low side at idle. Not sure what it should be. Usually most are around 20 psi. And yes, I brought the engine to running temperature before charging. Thoughts anyone?
