2nd Gen Non-Engine/Transmission A/C recharge question

[KStump]

I am currently in South Florida, and my a/c has quit putting out cold air. I've searched the forum and read the many posts on this subject. The first thing I decided to try is recharging the R-134. I bought a cheap guage and connected it to the upper port. With the engine running and the a/c on max, the pressure would cycle between 25-30 on the low end and 50-55 on the upper end. This was at about 5 second intervals. With the truck off, it reads right around 55. The optimum setting, I understand, is supposed to be 40-50. My question is, at what part in the cycle is it supposed to read 40-50? Should it be there on the low end, the high end, or can I set it with the truck off?



Also, I have dropped the fan housing and cleaned it and the drain tube. I checked all of the mixing and temperature controls and all are functioning fine.



I appreciate any help you guys can offer, or any other ideas as to what else the problem might be. Thanks!

 

[Fordiesel69]

Way to low on your pressure. You CANNOT measure high side pressure with those elcheapo guages. You need to go by the low side. The newbie way to charge is to do one can at a time and place your hand on the big line going into the comperessor. When it is nice and cold, do not add any more.



This is the hack way of doing it, you really should be using real manifold guages. Also have an A/C shop inject some real UV dye into the system not the cheap cans sold at autozone that is for diy'ers. The professional grade dye used at a/c shops can be checked with a cheap walmart blacklight and some yellow hunting or shooting glasses. Blanket the engine compartment ot wait till night to check for traces or yellow dye.

 

[jhoughton]

If by the low end if you are talking about when the compressor is running. Then the pressure you are looking for while running should be somewhere between 35-45. The compressor will not cycle on end off when the pressure is correct. Once the compressor is running and not cycling then you should again start to feel cool air again. Hope this helps.

 

[Makensmoke]

I'll second Jhoughtons post. I do it yourself'd my a/c a few summers ago and what it came down to is just what he said. When the truck is running fill it until the compressor stops cycling. (runs constant) I gave it a little more just cause too, don't know if you should, too much and I spose it wouldn't run at all due to too much pressure!



My a/c gradually got warmer year after year until I decided it wasn't working very good. Rather than spending big bucks I researched it and dove in as usual. For $7. 00 I had COLD a/c (well $7. 00 plus that install kit, probably $25. 00, but the kit can be used many more times) for the whole summer.

 

[KStump]

Thanks!

Hey guys, thanks for the help. Apparently I just didn't put enough in the first time. Hooked up another cartridge and filled until the compressor stopped cycling, and now I have wonderful cold air again. Thanks much!

 

[Mad Bomber]

Aircondition. Com: Automotive A/C - Tech Articles and FAQ's - Troubleshooting with Gauges FAQ Great web site to learn and Harbor Frieght sells a good set of gauges for about 60. 00