SR2K

So, 80+ degree weather is here, and higher to come, its time to finally figure out what is wrong with my a/c system.

I bought this truck last august and the A/C didn't work then. At the time I was only working in construction so being a bit sweaty when I got there wasn't a big deal. This summer I've landed myself a job in an office, so showing up neat and tucked and dry is more important.

I haven't really done much in terms of looking into it, dont know where to start really. All I know is that when I turn the **** to ac, outside temp air comes in.

Where should I start?

HardcoreFx4

Start by checking and seeing if you have any freeon.

SR2K

There is pressure in the system, so I assume that its freon, unfortunately I don't have a gauge so I dont know how much pressure. When I turn on the a/c system the clutch does not engage however after jumping the low pressure switch it does.

Next step?

13Harleyfan

Any system loses pressure over time, quick fix I don't recommend is the quick recharge cans, you will have no idea how much pressure is in the system or how much air and moisture are in the system which wrecks compressors. If there is pressure that means the system doesn't have a leak (all systems seep when not in use on a regular basis) so take it to a reputable shop and have them service it. They will try and sell you a dryer which would probably be a good idea along with an orifice tube.

gustrider4

Of course jumping the low pressure switch will engage the clutch. Im an expert in A/C and did my old explorer last year. I recommend since you do not have any guages is to by a can of freeon. R-134A. Turn the truck on. Hook up the can and override the low pressure switch. The system will suck in the freeon as long as the compressor is on. After about 15 seconds let go of the low pressure switch. The system will appear to go on and off, clutch engaging on and off. This is a good sign and means it needs more free on. When the compressor runs contionous, u should be good. Constantly shake the can upright. Do not over charge because you could blow the gaskets on the compressor. They do sell cylinders with a gauge on it.

tansupercrew

I agree with Harley, I would NEVER use those cans. You have no idea how much air and/or moisture is in your system, which is bad by the way. Normally a shop will charge about $100 to service it right. Money well spent.
If you jump the low pressure switch and the compressor runs, the only reason it doesn't work normally is too low of a charge.

SR2K

Well the reason I jumped it was to rule out clutch or compressor failure.

I'm thinking I'll buy one of the cans with a gauge, yes they aren't as good as a professional job, but I can't really afford to drop $100 on something that I don't strictly speaking need. Also, if the system still has some pressure, how could air and moisture get in anywhere?

gustrider4

bad sreader valve or the last person to do the job didnt suck the air out before adding gas. alot can go wrong with a a/c system easily. like i said. buy the 20 can and see what happenes. let me know

SR2K

But if the system is still under positive pressure, air can't leak in, air and moisture can't move against a pressure gradient. The system has never been serviced before, the previous owner said the a/c stopped working around the middle of last summer, just before I bought it, all of the service ports have covers on them still, and look to be in fine shape. I'll get a can this afternoon and let you know.

SR2K

Alright, I bought one of the cans with a gauge from harbor frieght (It was the same brand as advance auto for $15 less) and emptied it into the truck. After the full 18oz the compressor was cycling and building pressure, and cooling somewhat. I went back in bought a second refill can and after putting half of that in its maintaining a constant 25psi and is cooling effectively, so thats good. I'll keep an eye on it and see if it looses pressure over the next couple weeks, but given that its held pressure this long, I don't see it leaking out too quickly.