General Maintenance & Repairs - AC cycles on and off constantly

Hey guys, this is on my 2000 Sonoma, but shouldnt be much different than a camaro. Im a technician, but not too savvy with ac systems. I recovered the freon, opened the line and replaced the orifice. I also replaced the valve cores. I recharged the system to specs, but the AC compressor cycles on and off constantly. When I had it hooked to the guages, the high side would quickly rise to 400PSI then the compressor would cut off, then the low side would rise back up and cut back and the process would keep doing this. This means I have a restriction in the system correct?

High side is way to high. could you have over charged it? Why you asking here rather than having another tech you work with help? Lol

You didn't say you pulled a vacuum before you recharged it, did you? Air in the system will make pressure too high

Is your condenser fans working when AC is ON??? They should be. 400 On the high is a bit high. In a very worm day it can be normal to some extent. I would have to check the charts. If the low side is sucking down past 30 it will kick out the compressor if it is a CCOT system. Their are many different systems out their and they work entirely different. Do you have a LICENSE?? If not BE CAREFUL. BIG FINES!!!

Is your condenser fans working when AC is ON??? They should be. 400 On the high is a bit high. In a very worm day it can be normal to some extent. I would have to check the charts. If the low side is sucking down past 30 it will kick out the compressor if it is a CCOT system. Their are many different systems out their and they work entirely different. Do you have a LICENSE?? If not BE CAREFUL. BIG FINES!!!

Not every state requires a license. I can't imagine any state where you can buy cans of r-134a at walmart could fine you for doing ac work.

The FEDS control FREON NOT THE STATE!!!!! Once again be careful not saying you should not do it JUST BE CAREFUL. Also every ac repair job requires a reclaimer on site. FEDERAL REGS. Just saying.

The FEDS control FREON NOT THE STATE!!!!! Once again be careful not saying you should not do it JUST BE CAREFUL. Also every ac repair job requires a reclaimer on site. FEDERAL REGS. Just saying.

You're not required by federal law to be licensed. You are required to properly recover refrigerant though. You don't even need a 609 card to buy r134a, you do for r12. That is a certification not a license. I've worked in 4 shops in idaho and I'm with my 3rd company over seas subtracting for the military. I've never been required to get a license and like I said I work with the fed governent now. If you needed a license to buy r134a they couldn't sell it at walmart and every parts store

I stand corrected. You do need a 609 card to service automotive ac, but not to purchase refrigerant. I have one but no one I've ever worked for asked if I did, kinda weird. I was assuming you meant a state license, I've heard some states require different licenses for different things in addition to the normal certifications. Depending where you live I doubt anyone is gonna hassle you about it though.

If anyone is interested in getting the card it's an online test and something like $25

I recovered the system, pulled a vacuum for 15 minutes and charged it up to 1lb and 12oz, just like whats written on the blower. I asked the other techs there and they didnt have the slightest clue, we normally dont deal with this on nissans. One guy told me to clean the condenser fins, so ill try that out. I did notice the ac will stay on if your driving down the road, but at idle will keep cycling.

I recovered the system, pulled a vacuum for 15 minutes and charged it up to 1lb and 12oz, just like whats written on the blower. I asked the other techs there and they didnt have the slightest clue, we normally dont deal with this on nissans. One guy told me to clean the condenser fins, so ill try that out. I did notice the ac will stay on if your driving down the road, but at idle will keep cycling.

No one there does ac work on a regular basis? That sound crazy to me. If it works when driving them you probably aren't getting enough air flow across the condenser. Make sure your fans are working and blowing in the right direction, I've seen them wired backwards. Not a bad idea to blow the condenser our either way

No one there does ac work on a regular basis? That sound crazy to me. If it works when driving them you probably aren't getting enough air flow across the condenser. Make sure your fans are working and blowing in the right direction, I've seen them wired backwards. Not a bad idea to blow the condenser our either way

That makes sense. I have a mechanical fan on the sonoma. We normally dont deal with AC alot... just isnt something that normally does bad on newer nissans.

OK i see you dont get this!!!! You can still BUY 134 but not for long. Either way you can only top off a system that is IT. Ahytime you service an AC system a reclaim machine must be on site. I service stand alone systems as well as automotive. And if the unit is 134 you are telling me i dont need a license. Man you are miss informed on AC service my friend. Either way i dont care. Now post the readings on high air MAX COOL at 1200 Rpm's this will tell the story. So untill you post Manifold readings we are chasing BALLOONS. Post the numbers and the evap discharge TEMPS. This way i have an idea of what is going on!!!

Ac is working fine now, just a dirty condenser.

I had an 05 Altima in the shop the other day (some construction guys, we're a Chevy dealer). He had no A/C and claimed to have recharged it himself. Lo and behold he charged a 1.12 lb system to 2.69 lbs. Sucked it down, filled it up. No compressor action. Ended up being a compressor fuse missing! Always somethin stupid!

OK i see you dont get this!!!! You can still BUY 134 but not for long. Either way you can only top off a system that is IT. Ahytime you service an AC system a reclaim machine must be on site. I service stand alone systems as well as automotive. And if the unit is 134 you are telling me i dont need a license. Man you are miss informed on AC service my friend. Either way i dont care. Now post the readings on high air MAX COOL at 1200 Rpm's this will tell the story. So untill you post Manifold readings we are chasing BALLOONS. Post the numbers and the evap discharge TEMPS. This way i have an idea of what is going on!!!

Read my last post. I looked it up and I was wrong when I thought you don't need a 609 card, but that is a certification not a license. That's why I didn't agree with you, I thought you were talking about a state specific license. A certification is not a license. I've heard of states requiring licenses for different things in addition to normal certifications so I thought that's what you were talking about. You are right though that it's a federal law that you need a 609 certification. I've been a tech for 10 years and got the 609 cert at Wyotech in '02, so I've had it my whole career but no one has ever asked if I had it. But I live in Idaho and you can do whatever you want in Idaho lol.