A/C went from ICE cold to not at all
However, the most common causes for sudden AC failure is:
1. No vaccum to the interior controls, which causes the fan system to go into a kind of failsafe (i.e, no AC). The vacuum lines are the tiny ones behind the intake (on an LS1 at least). If you physically swapped the PCM, you might have accidentally disconnected one.
2. AC compressor gave up the ghost.
If it's zero, then nothings going to happen--it's off on a low pressure switch.
A lot of people mis-diagnose this thinking the compressor isn't getting voltage so it's electrical.
1st step. check the pressure. WITH A GAUGE.
I guess I should go on to say with a gauge because some people have also checked pressure by sticking a key or something in the schrader valve and if a little peep comes out they assume it's good.
Or on the other hand people just assume it's low, put a huge leak stop/uv dye/super cool gimmick can in the thing right off the bat and when they do find an electrical problem and get the compressor to run it still won't cool because then it's overcharged.
As far as vaccuum lines inside the cab, when i was looking behind the glovebox (running wires for my microedge) i accidently nicked into a thicker red tube, i thought it was a wiring bundle, now thinking about it it may have been vaccuum lines, there is a bundle of bright colored tubes, looks like wires but not (picture below). I didnt cut into it too much more of a puncture and wrapped it in electrical tape once i realized that it want wiring. Is this the vaccuum lines that you were talking about, could this be the issue, and if so how do i go about repairing them? This is the only other thing i can think that changed

Last edited by evilbeef54; Jan 24, 2009 at 08:46 PM.
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Ok, ALL of the vacuum lines do something with the AC and heat, and defrost.
Do the regular process of elimination--fix what you know is broken first, don't look for other things wrong yet.
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well i wanted to make sure because i also noticed the a/c not working after the PCM blew but that doesnt necessairly mean that the PCM was the problem, i do plan to fix those tubes, just not sure WTH they are so i dont know what parts to get, lol. Also i like to learn as much as possible about my cars, one item being, what are these darn lines, lol. Plus im not sure if the fix of tightly wrapped electrical tape "fixed" that line. If it is a part for the A/C then i think that the tape clearly wasnt a sufficent fix, if that is not related to the a/c then there may not be an issue. After reading through these posts though i'm assuming they are vaccuum lines and therefor AC related, is this correct

also any suggestions on how to properly fix these hoses?
Last edited by evilbeef54; Jan 24, 2009 at 11:08 PM.
The vacuum lines control the servos that open and close doors inside the ac box. They redirect air to different vents, open and close the heater door, etc.
The ac might be fine but the heat door is open and you've got ac and heat at the same time.
It's only a guess at this point. It's very difficult for me to diagnose stuff like this over the internet.
Without the ac on, say vent only, heat control set to cold(all the way counterclockwise) does it blow hot air, or outside air temp.
Does the compressor run?
Whats the suction pressure with a gauge, and what ambient temp was this read at?
Thanks
Thanks
You run over a nail and put a hole in it, the air leaks out. You air it up (luckily air is free), but you come out the next day and it's flat again, so you look for a leak and fix it.
Same thing with AC, if it loses refrigerant, there is a leak and any added will leak out and it'll stop working again.
Too bad refrigerant is regulated somewhat by the EPA, I'd invent a self serve refrigerant refilling station at gas stations so people could refill their AC units every other day for $27, I'd be rich.


