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The AC on my 99 C-1500 just blows air, not hot or cool, in the front and just slightly cool in the back. The compressor cycles on, and the gauge on the can of R-134 I bought at autozone reads just into the high "warning" section. The gauge is just barley into the overcharged section. I did not put any R-134 in.
Any ideas
 

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remove the freon and look at the orfice tube in the high side line bye the passenger side fender under the air filter box. the orficetube may be pluged and then add the freon back. first you can try removing some freon and see if the pressure go down the low side (BLUE) should be 30- 40 psi and the high side (RED) 200- 300 psi.
 

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OKay first you need to Google where your orifice tube.Gm's moved a great deal of them to them condenser in the front.If you standing in the front of the truck it would be on your left.High side should be in the 200psi range,slightly higher depending on ambient temps.Please do your truck a favor as well as yourself,unless you know to within an ounce or two don't just add freon,go to someone who has the tools to do a proper recovery,hold a vacuum and a correct recharge.
 

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most A/C shop with not vac. your unit it out for free. for the cost of the freon. can i ask why your questioning everything i say on all my posts. i am a A/c tech now and worked in a shop for over 10 years with A/C in Florida. where 10 months out of the year you use A/C.
 

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sorry nothing personal intended i have been an L1 master tech for 24+ years.If you read what i write and you know what i do,you know even if you have to pay someone to draw a vacum on the system and dye its better than the suicide kits they sell at AZ.No pro would ever tell someone to just a freon to a system without being aware of what it has in it already.R134a operates at to high of a pressure to get by with that.
Again i do this daily to offense meant. i was just trying to be helpful.
 

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Hi all, first time here. Just wanted to share a little info on what I'm learning about my '99' Suburban k1500 ac. Just replaced compressor, accumulator and orifice tube. The orifice tube on my '99' is found on the passenger side near the fender well about 12"-14" back from the fan shroud and about the same distance forward of the air cleaner box. Look for a fitting (nut) in the line and a dimple in the line about 5 " from the fitting. Take the fitting apart (be sure to use two wrenches) and you'll find the orifice inside the line forward of the fitting. I think the dimple in the aluminum line is to keep the orifice tube from being pushed too far into the line. I tried to remove the two line connections at the condenser (behind grill) and one came apart easily while the other was corroded and the threads were gone. This gave me the opportunity to go to the salvage yard to find another condenser. Why GM ever thought it was a good idea to put a steel nut onto aluminum threads is beyond me. Had I not been able to dig the aluminum out of the steel nut's threads with an ice pick I would also had to purchace a new hose set. :grrrrrr: So BEWARE !!!! taking apart those old steel/aluminum fittings may get real expensive! Everything is now bolted up except the hose block on top of the compressor but I first have to try to determine how much oil to add. There was no oil to be found in the old one !!
 

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Sorry, I'd like to restate where the orifice tube is at on my '99' GMC Suburban now that I've looked at it again in the daylight. It is in the alum. line right below the front edge of the air cleaner box and about 5" from the fan shroud on the passenger side. My guesstimated measurements on the above post last night were way off.
 
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