OT question about A/C

[kid]

If the system is half low there is no problem adding to the high side. When charged that is a different story trying to add even one ounce.

[71 LONG BED]

Well if I could find just 30 minutes I might get a chance to try this out.
Still haven't been able to get out there under the hood.
This weekend looks promising, but I'm not going to hold my breath. I'll keep you posted.
Oh yea, if I hook up to the wrong side, will there be an explosion?

[71 LONG BED]

Since it was 95+ degrees here today and it's supposed to stay hot for a few more, I finally got under the hood when I got home last night at 9:30. (never enough time...)I bought an AC gauge and checked the pressure. I checked it while the truck was off and was very surprised to see it was up to 120psi!! Oops, then I remembered it needed to be checked it while it was on max and it was just under 35psi. Right where it should be. It was darn near blowing icicles out of the vents. The compressor ran non stop for the 5 minutes I let it run.
Could it be the compressor is bad? Maybe after it heats up it craps out?
The refrigerant needs to be collected, no? That may make it not a "do-it-yourself".

[kid]

Freon needs recovered by a vacuum recovery system.

Was that low side or high side that you got pressure on? R12 needs almost 180 psi for good operation.

Icicles is what the old R-12 systems put out. THe Ford test was a thermometer in front of the inside vents. If the temp did not drop to 32 the system was bad.

[71 LONG BED]

Was that low side or high side that you got pressure on? R12 needs almost 180 psi for good operation.

That was the low side and it is an r134 system. I tried to test the high side and the fitting is different and won't accept the gauge.

This is the gauge I bought. When I checked it the needle was just shy of dead middle of the blue.

[Wes]

My can fills the high side while running the R134 connectors have a one way valve in them. Read the can you buy with fill hose.

I didn't know this never owned or used a kit hose, only have 20 year old manifold gauges and r134a/12r recovery/charge machine now. I haven't used a puncture can since 1993. Old school, can would rupture in your hand if you opened high valve.
I still don't see how you are going to get most of the gas from can, attempting to charge into a 150- 275 psi line, when the low side will be 40 psi or less.

[kid]

Oops sorry it had slipped my mind that we were on R134. A lot has been happening.

[71 LONG BED]

So what do you guys think? Is the compressor done? Any other ideas of what the problem might be? It blows nice and cold for about 5-10 minutes then starts blowing warm.
My poor wife needs some air conditioning, she's 7 1/2 months pregnant.

[kid]

It does not look like it has enough Freon.

[Fake Name]

Just a thought- I recently installed a new AC/heater in my truck and took it to the AC shop for the R134 fill. When I got in the truck at pickup, it was nice and cold, but within a mile or two, it started blowing warm. Turns out the heater valve was not adjusted correctly, and not shutting off completely. When the truck got warm, the heater started working, warming the cooled air.

Maybe you have a heater issue of some sort??

fn

[kid]

The valve might not close all the way by the cable or it leaks inside. Sounds reasonable as a cause.

Does the AC gauge read the same charge warmed up and running as it does static. We never fill Commercial or Residential units with out running them during the last part of the fill.

[71 LONG BED]

That is a very good thought fakename. Thank you. I'll check into that one, for sure. Ever since that dash was taken off I've noticed a few things were not quite right.

As far as needing more freon, it is right in the middle of the range it's suposed to be. How much more can it take?

[kid]

The gauge reads pressure. On a hot system there is more pressure than on a cold system. Fill it to the same pressure at night and the system will hold more Freon.

On commercial units it might say 5 lbs to fill from evacuated. Well we take the temp of the High pressure line and divide by the air temp entering the outside coil. We take the temp of the inside air and divide by the suction line temp. Then those two numbers are put into a supercool chart and our 5 lb system might need 7 lbs to be filled correctly. We are not looking for a book number but a corrected system fill number.

By the way filling it to the top edge of the blue area will not hurt it on a hot day.

[71 LONG BED]

Thanks Austin. I have determined that the cooling fan isn't coming on, so that may have something to do with it also. Unfortunately I haven't have any garage time at all lately. I hope things slow down when the baby is born. It just seems like there isn't enough time in the day for everything right now.
I will try to make time to try clamping off the heater hoses and I'll let you know what I come up with.

[71 LONG BED]

I checked right when my wife got the truck home from work last night. I figured I'd need to check it while it wasn't working properly and it was a very humid 90*+ day yesterday . I unplugged the sensor on the t-stat housing and the fan came on. So it's not the fan, maybe the sensor though, or maybe the truck just wasn't hot enough to kick the fan on. I also figured I'd try blocking the heater hoses. I clamped both, thinking that maybe the hose valve is bad and was feedeing hot air that was counter acting the cold. That wasn't it either. Then I checked the freeon charge. It was 120psi!! Then I realized the compresor wasn't kicking on at all.
I think I narrowed the problem down to the compressor failing to kick on after it's hot. My question now is, why would it stop kicking on after the truck is hot? You guys have been a big help so far, and I appreciate it very much.