Weird AC Problem

what is your bunk fan set at? the front works better with the back on zero.

if the system is properly charged and functioning. the compressor won't cycle. on some systems. low pressure doesn't get low enough. high pressure doesn't get high enough. to cycle the clutch.


you need gauges to verify pressures and switches are working properly

 

I had an AC problem a couple of months ago when the AC clutch would go out once I hit a bump then turn back on when I hit another one. The AC pressure switch was going out on me (connected to air dryer). Once I replaced that part AC ran great.

 

well what sounds weird to me is the fact that your blowing power decreases when the truck starts moving. Based on what I have read it sounds like a flap in the duct work is moving when the truck moves. That or another guess would be the blower motor losing power when you start moving, but i don't know about that one.

i might add like snowwy said, my compressor on my 03 Century never cuts off.

 

To even begin to diagnose an a/c problem you have to know that its charged to spec. An undercharged system from a slow leak is the most common cause of a/c malfunction. Given the symptoms you are experiencing that must be ruled out first.

 

Look under your dash for an obstruction at the recirc door. . Probably a Walmart bag or napkin has gotten sucked up there and is blocking the air being pulled from inside the truck. .

When it's on non recirculation it pulls outside air.

The blockage will cause poor air flow from vents. .it could also cause the evaporator to ICE reducing air flow even more. . Then when you idle it unfreezes giving you a sense of highest fan speed.

Recirc door is on passenger side below glove box.

**in another life I turned wrenches