AC not working

[IRA51]

You can see the end of the compressor spin if it is working . try haveing a friend turn on the ac while you watch the compressor. you will see and hear it engage if it works . If it won't go on it could be low on freon ,or the high preasure switch or connection to the high preasure switch could be bad . Or your ac head unit in the dash took a dump . Any ac shop can tell you whats wrong free ,fixing it will cost though .Good luck and be glad your not in Phoenix with out AC in the summer .

[draconianruler]

I just bought some freon and I'll try charging it. Hopefully that is the problem.

[draconianruler]

Does the Hummer use a special AC fill adaptor? When I connect the Freon can to the fill nozzel (smaller one), I get no pressure. If I squeeze the trigger to add nothing comes out. The conncection seems to be connected perfect. I checked by connecting and adding a little on my vette and it works. Am I doing something wrong?

[IRA51]

NO. THERE IS A HIGH SIDE AND A LOW SIDE PORT. FYI if you over charge the system you drive the head preasure up and blow the seals in the compressor ,be carefull . Have a good AC tec check the system for you . An over charged system will not get as cold as a properly charged system.

[draconianruler]

So it turns out you need a special adaptor to connect the pressure gauge/hose to the new refridgerant bottle. Apparently if you have a older pressure gauge/hose it will not work with the newer bottles (It might just be a CA thing).

The good news is that my compressor and AC does work when the refridgerant is full. The bad news is that I have a bad leak somewhere. After a day its all empty.

I bought some more refridgerant with the UV dye and looked for the leak but can't find it. You'd think it would be easy to find with such a bad leak. The only place I didn't check was the evaporator area inside the dash. Anyone ever pull out the dash to get to the evaporator core?

[IRA51]

WITH GM vehicles it is very rarely the evap core, check the condenser for impact damage. GM compressors leak at the front seal a lot .

[draconianruler]

Originally Posted by IRA51

WITH GM vehicles it is very rarely the evap core, check the condenser for impact damage. GM compressors leak at the front seal a lot .

I had checked the condenser and traced the lines and no leak (at least that I can see with the UV dye). I'll double check everything this weekend again before going into the dash.