AC Compressor Cycling 30 seconds

I did search and nothing matched exactly, got some ideas but not sure.

So this year I start up My 00 Jimmy on a warm day turn on the air and nothing but hot. So I go buy a recharge kit and a gauge. I jumper the switch from the compressor to get it to cycle and the guage needle goes from in the yellow to absolute dead bottom of green. So I fill her up, now if the compressor isnt running it goes up to the yellow almost to the red, but if it is it barely marks in the green and the compressor cycles on when it hits yellow and off after about 30 seconds when it hits back into green. It does get cold after running for a couple minutes like this, but I am worried about why it is cycling and the guage isnt staying in one spot. If i jumper it blows cold quicker but as well its still not the ice I had coming out last year.

I believe the compressor will do this no matter what. My compressor would kick in even during winter if I moved the temperature knob in the blue area. I don't believe the Blazers have an option where the compressor shouldn't kick in when the AC is not selected.

I did search and nothing matched exactly, got some ideas but not sure.

So this year I start up My 00 Jimmy on a warm day turn on the air and nothing but hot. So I go buy a recharge kit and a gauge. I jumper the switch from the compressor to get it to cycle and the guage needle goes from in the yellow to absolute dead bottom of green. So I fill her up, now if the compressor isnt running it goes up to the yellow almost to the red, but if it is it barely marks in the green and the compressor cycles on when it hits yellow and off after about 30 seconds when it hits back into green. It does get cold after running for a couple minutes like this, but I am worried about why it is cycling and the guage isnt staying in one spot. If i jumper it blows cold quicker but as well its still not the ice I had coming out last year.

To recharge a air cond right you need a proper recharge gauge set with a high and low pressure gauge. :grinyes: :lol:
If you have one hook up the gauges and give us your low and high readings at idle and at 2000 rpm.
If not find someone that does.

... Ten reasons why you shouldn't use those retrofit "death kits" found in Wal-Mart and other auto parts chains:
First, R-134a destroys the silica or XH-5 desiccant in the accumulator, which is why the accumulator needs to be replaced with XH-7 or an XH-9 R-134a compatible accumulator. Destroyed desiccant will circulate throughout the system, were it causes extensive damage. Clean up is very involved and expensive. Imagine the damage to your engine if sand were dumped down your oil fill, this is similar.
Second, since R-134a does not carry mineral oil, the compressor would be starved for oil. The kit solution? Add POE (Ester) oil to the system, and the existing mineral oil will miraculously find a "low spot" in the system until "future service". Sometimes this works. Problem is, what if that "low spot" happens to be your compressor? A compressor can't pump liquid, so imagine what would happen trying to pump jelled up mineral oil.
Third, considering the potential problems of leaving the existing mineral oil in the system, the compressor should be drained of the mineral oil, and the system thoroughly flushed. Flushing will also remove any residual chlorine, which adversely affects lower grade POE oils.
Fourth, a system must be vacuumed before refrigerant is added, and the last I checked, the $29.95 kit doesn’t contain a $299.95 vacuum pump. Air and moisture in the system will not only reduce performance (air will also raise pressures), but will drastically reduce the life of components. Moisture will cause expansion valves to freeze up, resulting in no cooling. Check the prices of various A/C components, they're often not cheap.
Fifth, you cannot safely and properly charge a system without a manifold gauge set. R-134a in an originally designed R-12 system usually runs a significantly higher pressures, sometimes dangerously so. Some kits include a low side gauge, but what about the high side? Say there’s a malfunction in the system, and the kit user just keeps charging until "safe zone" or "full" on gauge is attained. The high side pressure keeps rising to 350 PSI, then 400 PSI, then 450 PSI, and eventually kaboom!
Sixth, with respect to the higher R-134a pressures previously mentioned, a high pressure cutout switch needs to be installed (and is required by the EPA), but the kits don’t include one. If there's no high pressure protection, rising pressures will blow the system, or at minimum, shorten the life of components, particularly the compressor. If you're lucky, your system might have a dump valve that'll relieve the excess pressure. However, if the system keeps dumping refrigerant and oil, the compressor will be starved of oil and the system will fail anyway.
Seventh, to reduce the aforementioned higher pressures, a higher capacity condenser is often needed and fan and/or air deflector enhancements may also be required.
Eighth, because of the different pressure/temperature relationship between R-12 and R-134a, system controls need to be recalibrated or replaced. This could involve something as simple as adjusting the cycling pressure switch, or more involved like replacing an OT, expansion valve, or compressor control valve. Older vehicles with POA, VIR/EEVIR, EPR/ETR valves will likely be just plain out of luck. The controls on some vehicles – read Cadillac ATC – are so closely calibrated for R-12 that retrofitting is virtually impossible. Even some Ford vehicles control module replacement.
Ninth, the R-134a molecule is smaller than the R-12 molecule, so it will leak out faster. O-rings and seals require replacement with HBNR (green) O-rings and seals. A number of compressors are also incompatible with R-134a. Barrier hoses are necessary with R-134a, although older hoses having been coated with mineral oil over the years are said to have a "barrier" effect. The kit contains none of these items.
Tenth, by now you still need another reason not to use these kits?
In summary, while these kits "might" work, they usually don't for very long. And when the system fails, they usually take everything forward of the firewall with it, and the repair bills are often in the four digit range.

MT

Thanks for the long detailed explanation....

Still my 2000 never had R12, and I was wanting an idea on what might be wrong not all the reasons not to use something. No offense I liked learning all of that, however can I get an idea as to what I might need to have done, I dont like the idea of paying 80.00 just to have it looked at and that money be non refundable if i cant afford to leave the car their to have it fixed.

It is hard telling what that Wall Mart recharge kit has in it could even propane/butane for all we know.
But First thing first.
Pitch that wall mart recharge kit in the trash can.
If you want to recharge it or check it you will need a recharge gauge with a high and low pressure gauge.
There is no way you can check it or attempt recharge it right without one.
Get the pressure readings at idle and at 1500 rpm and post them back and we can help you on it.
Also here is a good link on AC repairing.
http://www.autoacforum.com/
MT

Thanks for the long detailed explanation....

Still my 2000 never had R12, and I was wanting an idea on what might be wrong not all the reasons not to use something. No offense I liked learning all of that, however can I get an idea as to what I might need to have done, I dont like the idea of paying 80.00 just to have it looked at and that money be non refundable if i cant afford to leave the car their to have it fixed.

On newer air cond systems just adding freon usually does more harm than good.
If they are very low you have a leak and very good chance the system has moisture in it.
Oil and freon leaked out and Moisture in a system will kill the compressure quick.
Newer systems need a set/exact freon charge. most around 2 lbs. a little to much or not enought and they do not work right and may damage compresser and other stuff and also the right and correct amount of oil.
Most of the time you are better off to get them pumped out/vacumed down to remove moisture and the exact/set recharge put back in them.
Unless you have the equipment to do it right a good repair shop should be able to do it. 1-1.5 hrs labor plus freon.
Or if you want to post back the pressure readings low and high we may be able to tell you more about what your problem is.
MT

A little more info on it.
I would suspect a major leak.
#1 Freon is non consumable, if it's not there then there is a leak
#2 A/C is a delicate balance between liquid/gas (low side/high side) and too much freon is just as bad as not enough
#3 If you are not prepaired to buy a set of A/C gauges, and be willing to possibly buy a vaccum pump or a/c die and replace the proper componets, then don't even waste your time.
#4 90% of the time your going to have to pull a vaccum, flush the lines and most the time replace the accumilator and the Oriface tube/expansion valve.
#5 The only easy fix is if one of the pressure switches is bad, there is no just add freon fixes.
#6 Please Please don't just add freon w/ a charging kit because you think it needs it, It doesn't work like that.
#7 These guys are a execlent source for help and if you listen to the procedures as you are told you will end up w/ some ice cold A/C, being hard headed is expensive.

http://www.autoacforum.com/

#8 And here is a link from AC kits.com to what a person needs to recharge a air conditioning.
A/C starter Kit
#9 Adding freon to a system that has a good charge can be dangerous and can cause you harm, if the pressures get to high and blow the freon can or something in the system.