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AC kicks out for 5 plus min and then starts working again.

WarWagon

WarWagon

Well it hits on 7 of 8...
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My favorite redheaded stepchild the 1993 pickup...

AC kicks out for 5 plus min and then starts working again. I ran into this a long time ago with water icing the orface tube. I just don't recall if it kicks out the clutch when this OT ice happens.

I would think the high side switch would kick back in fairly quickly if the condenser was overheating.

Charge looks ok from the low side and the system works perfectly. All of a sudden it kicks out the clutch and stays out for a trip across town. It is over 100 when it does this 1st time 103 and today 105. R134A converted system. Duramax fan and Hayden clutch. System was repaired last year: New hoses, accumulator, condenser, compressor... The low side switch valve leaked the system charge out when the valve was removed to pull the engine and may have allowed the system to pull enough water in to cause issues.

Not had a chance to check the switches to see if one is sticking or open to cause this. The shopping list of thing to fix this weekend...

Anyway can someone confirm how log the high side overpressure switch would keep the system off?
 
The high side pressure switch will keep the system out as long as the pressure is above the switch rating. Shouldn't be long. The second the compressor stops spinning the pressure is going to drop, since one side is lower in pressure than the other. The pressure is going to naturally bleed off to the side that's lower.

The junker car here is having A/C issues after its' been running for a bit. It kicks on and off very rapidly to the point where the car will start bucking. I just stopped using the A/C in it, but that's because i don't care about that car.

Just remember. R134A runs at higher pressures than R-12. That could be part of your issue.
 
You need to get a set of gauges on the system and see what the pressures are.

With the compressor running the low side should drop to the mid 30's and the high side should be around 175 to 200 PSI (Depending on how hot it is outside)

If the pressure on the high side goes into the ozones (High) then you have a blockage.

If the pressures are reasonable then the high side safety switch could be bad or even the low side switch on the accumulator (large silver can) could be failing.

If your pressures are low all around then the system is low on refrigerant.

If the pressures are in the ball park and still no joy, check the high side and low side switches with a Meter to be sure that they are not staying open.

Either of the switches can fail.

Keep us posted

Missy
 
:rof:
My 93 is doing the same thing. Intermittent problems like that are a bitch cause when you stop to check, damn thing starts working. Any way I threw a test light in mine and when it cut out , I pulled right over and sure enough power going to cycle(on the dryer) switch but nothing coming out and system was charged. I actually have the switch coming in today but I suspect it may be the plug but the friggin plug was 32$ so I gambled on the switch itself but when I wiggled it around it came back to life for awhile. I took a pick and bent the female pins closed more and scraped them clean to no avail so either the wire is damaged by the plug or the swtich is bad. I ain't payin 3$ for a friggin plug with a pigtail. I gotta hit the junky this weekend anyway for a steering wheel and some exhaust hangers so a plug will find it's way into my tool box...:D
Hope that helps.
I had a KW one time that the guy took to Kenworth and they could not figure out why his kept cutting out(after charging the guy up the ass for all kinds a crap). Everytime I checked it it was working but then he'd head out the next day and it would die. I finally had to hook up a small 194 lightbulb and socket to his dash(just hanging) and wired it to the hot side of the compressor clutch and told him to drive the truck and report back if the light was lit or not lit when the a/c crapped out. Turns out the a/c clutch had a break in the winding that was cutting out after itt got hot or something..Anyway, new clutch..problem solved but what a PIA. Intermittent problems suck. Like I said carry a test light and pull over the second it cuts out and try to test.

I have not ruled out the possiblity that the schraeder valve is f'd up too and not giving the switch an accurate reading but I'll try the switch first.
 
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I bet that schraeder valve may be it as it was letting the system charge out. Damn made in Communist China Accumulator...

I have a test meter and jumper wire with me now. Low side pressure was high while cooling. But it is 105 out...
 
Found he engine vibration had backed a pin out from the high side switch connector. Bumping the connector caused the clutch to pull in and out. Replaced the connector...

Also read a large clutch gap can cause this when the coil gets hot.
 
I had a less than a year old low pressure/cycling switch go out. It acted like it was freezing up, you could turn the a/c off for a couple mins and it would work again for a little while.
 
X3

What was bad it was an AC/delco that went bad, prolly made in china though. The parts store didn't have a Delco to replace it, so I got an off brand one, the plastic threads stripped and blew off as I was screwing it on, the second off brand one is still holding so far.
 
WarWagon said:
Found he engine vibration had backed a pin out from the high side switch connector. Bumping the connector caused the clutch to pull in and out. Replaced the connector...
Also read a large clutch gap can cause this when the coil gets hot.
Click to expand...
Glad to hear you got it sorted out. I've driven through Phx number of times w/o A/C in the summer and when I was younger I used to work for a cable TV company there and the van didn't have it either. "Melting! I'm Melllltttiinnnnggggg."
 
Paveltolz said:
Glad to hear you got it sorted out. I've driven through Phx number of times w/o A/C in the summer and when I was younger I used to work for a cable TV company there and the van didn't have it either. "Melting! I'm Melllltttiinnnnggggg."
Click to expand...

The AC failed 4 times last year before, well, the only thing not replaced is the evaporator.

Last time I blew the clutch on a 30 day old rebuilt compressor I was towing of course. I was lucky it blew 2 blocks from where I was going with the trailer. I then removed the shattered clutch and drove home w/o AC. It was 115 out and felt like a blast furnace with the windows down. My feet felt like they were on fire from the air on the floorboards.
 
Glad you figured out your problem, for others with AC issues don't forget about orifice tube used in the GM A/C system junk from an older system that has been in service for years or has had leak detector/sealant put in system can clog the tube/screen which also can cause high head pressures and errant operation of your ac system.
 
I am adamantly against the use of tracer dyes. One thing my father taught me many years ago, if a truck comes in loaded with tracer dye, send it somewhere else...I realize the stuff is better than it was 30 yrs ago but I still don't like it and I think I needed to resort to it once in the last 20 yrs.
 
Acesneights1 said:
I am adamantly against the use of tracer dyes. One thing my father taught me many years ago, if a truck comes in loaded with tracer dye, send it somewhere else...I realize the stuff is better than it was 30 yrs ago but I still don't like it and I think I needed to resort to it once in the last 20 yrs.
Click to expand...

My suburban has it because the battery powered leak detector could not find any leaks. The dye is showing a slow leak at the hose crimp fittings. So hoses will be replaced if the system fails or over the winter. Good stuff really. Used it in the past to see the compressor body o rings slowly leaking on a 88 pickup.
 
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