Any air conditioner experts out there? My dash air was operating just fine until a couple of days ago. Here's the deal. I start the rig and turn on the dash air. I can hear the compressor pull the engine down just a bit like usual. Soon, the air blowing from the vents begins to cool. Gets down to the high 50s (85 or 90 outside) and then cooling stops and the air warms. I watched the compressor and see it run at startup, however, after five or ten minutes the compressor starts cycling on and off, mostly off. It will run for 5 seconds, shut down for 45 seconds to a minute, run for 5 seconds and so on. The condensor fans are up front and I see they are running. I don't have gauges but I do have a can of 134a and one of those cheapy hose/gauge deals. I hooked it up to the low pressure side and see around 40 when the compressor is running. Then it jumps way up to 90 or so when the compressor quits, back down when it starts and so onlI need to take the rig in to check a brake and wheel bearing and I'll have them take a look at the A/C too. Anyone have an idea of what's going on? Thanks.jor

Short cycling is an indication it could be low on charge. But you really need to fix the leak before re-charging it.

On a 95 Foretravel I would not worry about a leak if this is the first time in 4-5 years. Add 1/2 a can of 134 and see if it stops cycling. I use a IR temp gun on the condenser coils to see when 90% of them are hotter than the last one to judge how much more freon to put in. One can should be more than enough so do it yourself for $15 or have them do it for $100.

First Take a look under the front of the RVFind the evaporator and the big 12v fan, looks like trans coolerMake sure that fan is running2 yrs ago mine died and I had exactly the same symptoms, IWhen checking and testing I found the fan 25 amp fuse was bad, replacement blew as soon as I turned on the A/CReplaced the fan with new one from AutoZone, take the old one in when shopping for new one

If you have no airflow over the condenser like a bad fan or blocked by plastic bag or something, it could kick off due to high side pressure cutoff.Most likely its the low side pressure switch due to low charge or bad switch.....I had one fail once.This is all assuming you have a CCOT type.....cycling clutch orifice tube and not an expansion valve type.

MrWizard wrote:First Take a look under the front of the RVFind the evaporator and the big 12v fan, looks like trans coolerMake sure that fan is running2 yrs ago mine died and I had exactly the same symptoms, IWhen checking and testing I found the fan 25 amp fuse was bad, replacement blew as soon as I turned on the A/CReplaced the fan with new one from AutoZone, take the old one in when shopping for new oneCondensor, NOT Evaporator. The OP states he has checked and it is running. Doug

Cycling A/C Compressor | Good Sam Community

26 Replies

dougrainer
Nomad
May 25, 2014
If it gets to the hi 50's then the charge is not a factor. Low charge would cause short cycling at the beginning. I would suspect a BAD tstat. Jump the 2 wires on the Tstat (the tstat is at the Evaporator) and see if it stops cycling. Doug
dougrainer
Nomad
May 25, 2014
MrWizard wrote:
First
Take a look under the front of the RV
Find the evaporator and the big 12v fan, looks like trans cooler
Make sure that fan is running
2 yrs ago mine died and I had exactly the same symptoms, I
When checking and testing I found the fan 25 amp fuse was bad, replacement blew as soon as I turned on the A/C
Replaced the fan with new one from AutoZone, take the old one in when shopping for new one

Condensor, NOT Evaporator. The OP states he has checked and it is running. Doug
marcsbigfoot20b
Explorer
May 25, 2014
If you have no airflow over the condenser like a bad fan or blocked by plastic bag or something, it could kick off due to high side pressure cutoff.

Most likely its the low side pressure switch due to low charge or bad switch.....I had one fail once.

This is all assuming you have a CCOT type.....cycling clutch orifice tube and not an expansion valve type.
MrWizard
Moderator
May 25, 2014
First
Take a look under the front of the RV
Find the evaporator and the big 12v fan, looks like trans cooler
Make sure that fan is running
2 yrs ago mine died and I had exactly the same symptoms, I
When checking and testing I found the fan 25 amp fuse was bad, replacement blew as soon as I turned on the A/C
Replaced the fan with new one from AutoZone, take the old one in when shopping for new one
Ivylog
Explorer III
May 25, 2014
On a 95 Foretravel I would not worry about a leak if this is the first time in 4-5 years. Add 1/2 a can of 134 and see if it stops cycling. I use a IR temp gun on the condenser coils to see when 90% of them are hotter than the last one to judge how much more freon to put in. One can should be more than enough so do it yourself for $15 or have them do it for $100.
sch911
Explorer
May 25, 2014
Short cycling is an indication it could be low on charge. But you really need to fix the leak before re-charging it.

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Cycling A/C Compressor

26 Replies

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