98 ac problem

[blkmonday]

i have a 98 blazer. my ac isnt working....when you put the ac on the compressor will only engage for about 3 second and then it disengages..when its engaged it is sending cold air, it just wont stay on. it keeps cycling on and off but only staying on for 3 seconds. any ideas? my home ac harger with the guage reads that the system is charged?...probably should have asked this back in june...but its my wifes truck, my caddys a.c. is just fine
thanks in advance

[inafogg]

hello monday,sounds like the system is under charged(cycling on/off)what are the pressure readings???

[blkmonday]

the gauge on the refill can says 65 when the compressor is off and 25 when it is on...but i noticed the gauge leaks a little...so im wandering how accurate it could possibly be. this can has been sitting in my garage for a couple of years. i think im going to try a new one before taking it into a shop for re-charge. does it still sound like its undercharged? im clueless about a.c. systems

[blkmonday]

what exactly am i shooting for on the gauge if the system is charged...and should i read that when the compressor is on or off, because the gauge goes up and down when the compressor is on and when its not...like i said the compressor isnt staying on for more than 3 seconds...although when i added a little refridgerant it stayed on a little longer, so i think you are correct

[inafogg]

yes it sounds like it.you're about a lb low readings of 30lbs on low side is what you're looking for.good luck

[MT-2500]

To recharge or check a AC you need both the low and high side gauge set.
Drop them one hose one gauge walmart kits in the trash can.
And do not use the walmart death kit r-134a stuff with stop leak or any oil fit all

http://www.ackits.com/merchant.mvc?S...erantGaugeSets

If compressurer kicks on and off jump the low side switch if it is a 2 prong switch.
If not you need to jumper the compreser clutch.
Get the low and high side readings at idle and at 2K rpm.
Post back low and high side readings with copresser running.

If lowside is cycling below 25 lbs real often it is low.
If pressure is are low you might add 12 oz can for testing.
But watch both low and high side pressure when adding.
Do not lt high side get much over the 300 lb range.

If system is that low it needs checked for leaks and pumped down and the correct R-134a charge and the right oil added.

A good system reading is 28-32 low side and 200 -250 high side.
MT

[blkmonday]

hahaha thats funny how you knew right away i had a kit from wal-mart. your right it is garbage...im going to chuck it and have it done at my buddys shop as opposed to buying a decent set of gauges that ill probably hardly use. thanks for the advice guys! as always this sight rocks!

[MT-2500]

You are welcome and 10-4 on doing it right.
Good Luck and let us know how it goes.
MT

[blkmonday]

yup...just needed a recharge...75 bucks at the local shop. ice cold air. money well spent....now if i can just return that other crap back to wal-mart

[MT-2500]

No problem.
Just be nice but be firm and demand your money back.
Show the return person a copy of Walmart death kits posted below.
And let him know you have plenty more copys to pass out if they do not give your money back.

If they do not give it back take a hundred or so copys of it and start passing them out at the front door or parking lot.

Good Luck


Copy this off.
Wal Mart DEATH KITS
You cannot properly and safely recharge an air condition system with them.

The one side stop and go gauge does not tell you what your system is doing or is over charged or undercharged.
A overcharged or malfunction air condition system can reach over 500 lbs of pressure.
Enough to blow up that can or system and freeze you at first and the burn you or blind you and if any propane /butane in there blow and light you up.

The stop leak crap and who knows what kind of oil in the kits there will stop your system for sure.
Just like pouring super glue in it.
And some kits even contain freon with a butane mixer.
Good for a big blast.

If you are going to do it do it right and safe.
Here is what you need to start with.
http://www.ackits.com/merchant.mvc?S...erantGaugeSets

In the older days you could just throw in a can and go.
But over the years just adding freon is getting harder to do.
Newer systems have to have the correct amount of freon down to the ounces.
Most will need pumped down and vacuumed down and the right and amount of oil and a set amount freon charge installed to get the air to cool right and the system to last.
If an air condition is low there is usually a leak that needs fixed and also a lose of lubricating oil from system.
Also air and moisture enters a low system
If you are going to try to do it get the proper type air condition gauge set with the low and high side gauges.
Hook up the gauges and get a reading with compressor running at idle and at 2000 rpm on the high and low side.
Post back pressure reading and we can help you.
MT