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Topic: Compressor runs more often in cold temperatures. (Read 525 times) previous topic - next topic

Compressor runs more often in cold temperatures.

Seems like the auxiliary compressors are getting a lot of attention these days, so I'll add my latest question.

We were noticing the compressor running much more often when temperatures got below 45 degrees.  The lower the temperature, the more often it runs.  We had an overnight in Marfa where it got to the low 20s and it ran so much I ended up pulling the fuse. 

Just went through maintenance of the compressor.  Replaced the pressure switch, the essex relay, and the solenoid to expel water on the lower bowel. Checked all the wiring and used the spray bottle to check for for leaks.  All seems to be airtight.  (I haven't checked the bladder for leaks, but all the fittings up the that point.)  However, its following the same pattern, the lower the temperature, the more often the compressor comes on.

We use auto-leveling or manual, depending on the campsite.  If it auto-levels the first time in, we tend to go with that.  If we have to use blocks under tires, we'll get it level and then manual level as needed.  With auto-level off, it cycles on a little less often, but same pattern.  Colder it is, more frequently the pump cycles.  In the upper 50s, it might just be once or twice a day.  Lower 40s, 5 or 6 times a day. Haven't had it colder than that since maintenance.

Anyone seen this with their coach? 
Joe Phebus and Jaime Trujillo
2002 U270 3410  Build: 5953 Motorcader # 18595
2100 W Solar, 600 AH Battleborn Batteries,  Victron Multi-Plus II 3000 Inverter, Cerbo GX, & MPPT Chargers
1992 Geo Tracker

Re: Compressor runs more often in cold temperatures.

Reply #1 –
Quote from: Joe Phebus –
Anyone seen this with their coach? 
Yes - I had the very same symptoms until I finally chased enough of the leaks down.

1) Air gets smaller when it's cold. (technically, molecules move less). Pressure in the rear tank will therefor drop and trigger the pressure switch that activates the compressor quicker. It also makes it easier to escape out of your bags...thus triggering autolevel to work more.
2) Air fittings/connections/lines will also shrink in the cold creating more leaks in the system. I thought I had my rig pretty air tight this summer but once winter rolled around, areas I had previously inspected thoroughly formed new leaks by just sitting there. If you're going to chase leaks effectively it needs to be done in the cold
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Compressor runs more often in cold temperatures.

Reply #2 –

Another thing I will add is that I found far more leaks when I started using a higher quality bubble solution. Some leaks take a long time to form bubbles so if the solution doesn't cling, they're easy to miss; especially the kind that are on the fringe and tend to be more noticeable in cold weather. I've been using this most recently and like having the ability to adjust the viscosity so I can get more of the "cling factor": https://www.amazon.com/gp/product/B008MB1ZGW

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1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Compressor runs more often in cold temperatures.

Reply #3 –
Colder temps,more leaks,warmer temps less leaks.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Compressor runs more often in cold temperatures.

Reply #4 –

Joe, this is the remote switch I installed on our compressor.  When running the slide in and out, I turn it on, when I level, I do the same than when done, I shut off the compressor with the remote switch and no more compressor coming on and off!
Hope this helps:

dstfuy Wireless Remote Switch 12V,DC 12V/24V/48V/72V/40A Relay,Wireless RF...

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Joe & Dottie Allen
Sold!  December 2023.      2000 U320; build # 5645
Our coach " Maxine"
Motorcade #  15922;  Escapee 150950; FMCA F330833; Boondockers Welcome;  Harvest Hosts;  Thousand Trails
'98 U320 from 2000-'06
USAF '62-'66

"Do not spoil what you have by desiring what you have not; remember that what you now have was once among the things you only hoped for." ―Epicurus

Re: Compressor runs more often in cold temperatures.

Reply #5 –
Quote from: juicesqueezer –
Joe, this is the remote switch I installed on our compressor.  When running the slide in and out, I turn it on, when I level, I do the same than when done, I shut off the compressor with the remote switch and no more compressor coming on and off!
Hope this helps:

dstfuy Wireless Remote Switch 12V,DC 12V/24V/48V/72V/40A Relay,Wireless RF...

Nifty!  I just installed a toggle switch on the compressor the other day so I don't have to pull the fuse on cold nights.  I like this remote idea.  Thanks, Joe!
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
Joe Phebus and Jaime Trujillo
2002 U270 3410  Build: 5953 Motorcader # 18595
2100 W Solar, 600 AH Battleborn Batteries,  Victron Multi-Plus II 3000 Inverter, Cerbo GX, & MPPT Chargers
1992 Geo Tracker

Re: Compressor runs more often in cold temperatures.

Reply #6 –
my aux compressor won,t stop .. so i pulled the fuse.... it leaks air through bottom exhaust and just won,t stop ??

where can i get a chart to troubleshoot ? we have a 2003 U320
Ann & Carl Cote
2003 U320 4010T
cummins 450
Chevy Sonic

Re: Compressor runs more often in cold temperatures.

Reply #7 –
Quote from: ccote –
my aux compressor won,t stop .. so i pulled the fuse.... it leaks air through bottom exhaust and just won,t stop ??

where can i get a chart to troubleshoot ? we have a 2003 U320


Leaking air for the aux compressor is "normal". There should be a check valve between the aux air compressor and the bus air line. If you haven't replaced that check valve, most likely it is not going to hold pressure after so many years. That could cause the aux compressor constantly running. For my old U300, I replaced the gasket but still have air leaks around the compressor. Changing the check valve helped reduced the run time of the aux compressor a lot.
just FYI
1991 Grand Villa U300