A/C problem 1997 Silverado 350 5.7

[nahudson]

My AC is no longer working it just blows air, it seems to be just outside air that blows in. It is not cold or even cool

I am a very amatuer mechanic and was wondering if anyone had any ideas on what could be wrong or at least what to check out to try to trouble shot the issue

Thanks!!!

 

[BMWED]

Got the same problem on my 98. In my case the clutch is not engaging. Not had a chance to trouble shoot it. Is yours engaging? If not, could be the relay.
Ed

 

[ddawg16]

If your asking these questions.....it is most likely outside your abilities.

The most likely cause is low Freon level.....there 'is' a relay...pressure relay...if the pressure on the low side gets to low, it turns off the clutch. Unless the system is totally empty, when you first turn on the AC, you should see the clutch engage....and as it starts to pump, the low side drops and it kicks out the clutch....

The most common sympton that your Freon charge is getting low is an increase in the cycling of the compressor clutch. If you can't tell when it kicks in then your not paying attention to what your engine is doing....get to know your engine.

Charging up the system is only a temp solution...you have a leak...that needs to be fixed....

Time to find a decent AC shop and take it there.....sorry, but based on what your saying...it does not sound like a cheap solution.

 

[unkangler]

A common problem on these is the pressure switch on the accumulator. Tap lightly on the switch with the engine running and the A/C on. If the clutch engages and the system cools - you have a bad switch. Hope this helps.

 

[jay50]

Do yourself a favor, and do not try to jack around with AC if you don't have the training and experience.
And whatever you do, don't even think about putting that stop-leak **** into the system thinking you will solve the problem, you will only create more expensive problems that will have to be repaired.

Now, if that is the original AC compressor, there is a good chance that you have a refrigerant leak at either the front shaft seal, or the compressor case seal. I always check those areas closely when that vintage of truck comes into my bay with ac complaints.

 

[Lotek]

Common sources of leaks on these are the compressor(look for oil seepage at the seams and at the bottom), and the cycling switch (oil at the o-ring or inside the electrical connector). If the compressor is cycling on and off with no signs of leakage, it may just need a recharge. Make sure they add some dye to help with future leak detection. In any event this is a job for a pro, DON'T use one of those sealer/recharge kits that you see at the parts store, it will only cost extra when you get it fixed properly. A control head or relay fault is also possible, yet another reason to take it to a pro.

 

[foolishpride]

My '97 Silverado did that one time. The electric plug that plugs in the evaporator was loose. I think that's what you call it. It's on the passenger side, under the hood. It's an aluminum cylinder, with a black plug on the side of it. Check that plug.

 

[Heavy Metal Doctor]

All good advice so far....
I'll do anything mechanical, but I know enough about AC to know that without the right tools and specialty equipement you're pretty much wasting your time and could potentially cost yourself more money in the long run.
Take it to a decent shop you trust and ask them to go through it / fix it right.

My 97 Tahoe was leaking down and needed a recharge 2 years in a row . So, the second time around, I had my favorite shop check it over right. It ended up needing the top hose assy. at the compressor.

 

[old ladys mad]

done to many hose asy. and compressors to think about a #. have it checked dont be alarmed at the price , its high. it cost to be cool.

 

[Jake's '97]

I'm not a trained professional, but I have educated myself on air conditioning systems using available sources. Most A/C fixes on a system of this vintage, are easily done, except for an evaporator swap. All you need is a cheap set of gauges and a vacuum pump from Harbor Freight. You can bypass the head unit if necessary.

 

[J66442]

my 1994 gmc with a 5.7 had a similar problem. I bought one of those freon recharge kits and could hear the leak at the front seal of the compressor. I bought a new compressor and drier on E Bay, vacum pump and guages from Harbor Freight and I was good to go. There must be a tiny leak somewhere because twice I have had to add a can of freon (original repair was in 2007).

 

[LS6 Tommy]

Look at the insulation on the underside of your hood, directly above where the compressor is when the hood is closed. If it has oily strips on the insulation parallel to the compressor pulley & belt it's most likely a front compressor seal.

Tommy