94f150-5.0

Bought my truck a few years ago with a seized AC pump. I finally got around to putting another one in its place. When I turn the **** in the AC position the pump does not come on. There is power in fuse 6 for the AC pump. No power at the AC clutch plug. The system has not been charged yet. Is there a pressure switch that doesn't allow the pump to come on if the pressure is to low?

Thank you
Willie

digitaltrucker

needs charge, low pressure switch is protecting it most likely

94f150-5.0

Ok, thanks. I'll charge it and try it again.

94f150-5.0

So I charged it with a 14 oz can and the pump would come on for a second then shut off again. So I got another 12 oz can and now it stays on for 10 seconds. I guess it needs more yet. Every time the pump comes on the gauge goes down to about 28psi then it shuts off. The vent temp is 47 degrees so at least I know it's cooling. Is it normal to use so much freon? I changed the accumulator too.

77Ranger460

There should be a label on the truck showing how much refrigerant the system holds. It is likely close to 3 pounds. Usedan properly, the gauge you have will let you know when you have enough in.

digitaltrucker

did you evacuate the system before you charged it? If not, the system has air and moisture in it and it is contaminated!

You need to recover the system, evacuate it for about 45 minutes and then recharge to the amount on the under the hood label.

MORE IS NOT BETTER!

94f150-5.0

That's where I went wrong. I'll have a shop evac and charge it for me. At least I know it's cooling