Hi everyone. I'm having problems with the a/c in my 96 express van. Here are the facts:
it's a 350 with dual air
164,000 milesIt worked until a couple weeks ago.
It still sort of works, but doesn't blow cold now.
The compressor is turning on.
I can switch from (not very) cold to heat with the dial on the dash so I don't think it's a problem with that door that redirects air through the heater core.
I bought a $12 low-side gauge and a couple bottles of 134a.
The low side measured about 30-35 psi at first.
I tried to add a can of 134a. It sort of added some, but there's still some in the can. The low side pressure reads about 45psi now.
It's 90-100 here in chicago now.
After adding the 134a, the back is sort of marginal now, but better. My wife says the passenger side duct is cooler, but still not like it was. The driver's side ducts are still too warm, but a little better than they were.
I havn't measured the high side since I don't have the right gauge.
I have no reason to believe that the radiator area is full of leaves or something, but I havn't checked. The cooling system is otherwise working perfectly in spite of the heat.
When I added the 134a, it was at idle with the air on max and recirc.
I'm pretty sure it's not freezing up. It consistently doesn't work.
Can anyone suggest something else to check?
How does the dual air work? Is there another high/low side somewhere, like I charged the back but not the front, or is it all one system? I can only find the two ports.
The instructions that came with the gauge say that 45 psi is the limit. But that on hot days, maybe it could be higher. Is this right? What number should I be aiming for?
I've also heard that the low side pressure could drop when you run the engine at 2000rpm or so. Should I be adding 134a at 2000 rpm and make it read 45 psi at that time?
thanks.
brian