A/C not right in 2000 Bravada

[tlane276]

I have a '00 and the air works great sometimes and not so great others. Today it got up to 90 degrees outside and my ac was all over the place. It ran freezing sometimes and warm others. Sometimes when I got off the highway and slowed down, it got really cold and when I got my speed back up, it started blowing warm air. I dicked around with the knobs and buttons and nothing changed. Than I got out, turned the truck off, got back in and it worked fine until I had to turn the air down because it got too cold. At one point I turned the heater on full blast to see if THAT was working right and as soon as it got hot, I turned the air back on and it blew real cold air for about 2 minutes and then the air started getting warmer again. Any ideas?????

[MT-2500]

Automatc or manual AC controls?
Is the system getting good engine vacuum?
Any vacuum leaks?
Any check lights flashing or on?

Does the compressor shut down when it quits cooling?
Does the compressor cycle on and off very much?
Is the drain pipe draining water?

[tlane276]

Originally Posted by MT-2500

Automatc or manual AC controls?
Is the system getting good engine vacuum?
Any vacuum leaks?
Any check lights flashing or on?

Does the compressor shut down when it quits cooling?
Does the compressor cycle on and off very much?
Is the drain pipe draining water?

Both manual AND auto are working fishy. No lights come on. Sometimes it seems as if the fan runs faster. It cools til I hafta turn it down because it gets too cold. As far as the pipe, I dont know. It ran great til today.It works fine for a bit, then blows warm. Could it be something simple that a non-mechanic like myself could repair or would it be wise to just take it to a shop?

[tlane276]

Went out in it again last night and it blew warm air the whole time. No cool air at all. Not on auto setting or manual.

[MT-2500]

Watch the AC compressor.
Does it run or not run when it is putting out warm air?

[tlane276]

Originally Posted by MT-2500

Watch the AC compressor.
Does it run or not run when it is putting out warm air?

Sometimes it sounds like it is running and sometimes it kicks in. Spose I better jst bite the bullet and take it to an ac shop. thats some weak sh*t!!

[MT-2500]

Ac or a good repair shop.
Automatic controls should set a code if there is a problem.
Could be low on R-134a or pressure switches or wiring or even a bad AC compressor clutch.
Good luck
MT

[tlane276]

Originally Posted by MT-2500

Ac or a good repair shop.
Automatic controls should set a code if there is a problem.
Could be low on R-134a or pressure switches or wiring or even a bad AC compressor clutch.
Good luck
MT

my buddy says I just need to get my unit recharged. im gonna give it a couple more days and see where Im at. thanks for the fyi.

[MT-2500]

Originally Posted by tlane276

my buddy says I just need to get my unit recharged. im gonna give it a couple more days and see where Im at. thanks for the fyi.

He could be right But.
Stay away from them ONE hose one gauge wall mart death kits.
And the so call blends.
Do it right with a low and high side recharging gauge set.
And use the proper amount of R134a and proper oil.

Wal Mart DEATH KITS

You cannot properly and safely recharge an air condition system with them.

The one side stop and go gauge does not tell you what your system is doing or is over charged or undercharged.
A overcharged or malfunction air condition system can reach over 500 lbs of pressure.
Enough to blow up that can or system and freeze you at first and the burn you or blind you and if any propane /butane in there blow and light you up.

The stop leak crap and who knows what kind of oil in the kits there will stop your system for sure.
Just like pouring super glue in it.
And some kits even contain freon with a butane mixer.
Good for a big blast.

If you are going to do it do it right and safe.
Here is what you need to start with.
http://www.ackits.com/merchant2/merc...uct_Code=66773

In the older days you could just throw in a can and go.
But over the years just adding freon is getting harder to do.
Newer systems have to have the correct amount of freon down to the ounces.
Most will need pumped down and vacuumed down and the right and amount of oil and a set amount freon charge installed to get the air to cool right and the system to last.
If an air condition is low there is usually a leak that needs fixed and also a lose of lubricating oil from system.
Also air and moisture enters a low system
If you are going to try to do it get the proper type air condition gauge set with the low and high side gauges.
Hook up the gauges and get a reading with compressor running at idle and at 2000 rpm on the high and low side.
Post back pressure reading and we can help you.
MT

[MT-2500]

In reply to you PM it is better to keep everything in your post.
That way everyone can read it and help with it.
PM mail is more for private stuff.

Now if the compressor kick off and stay off a long time when you speed up the engine it is a good sign you are low on R-134a.

You need to run a low and high side presser test on the ac system.

Post back low and high side readings at idle and at 2K rpm with compressor running. You may have to jump low presser switch to get the compressor to run for the test.

And yes a DIY can do it in the USA Canadian laws may be different on it.
But here is some of the stuff you will need.
http://www.ackits.com/merchant.mvc?S...egory_Code=DIY

The first thing and the main thing you need the most is a AC recharge gauge set with the low and high side gauge.