Reply
 
Thread Tools Display Modes
Old 10-13-2018, 09:39 PM   #1
Junior Member
 
Join Date: Oct 2018
Posts: 6
Dometic air conditioner issue

I have an issue that just started with my Dometic A/C unit on our Sprinter travel trailer. As soon as the my rig is plugged in to a land line, the A/C unit starts. I climbed up on the roof and it seems the compressor is running and there was definitely heat coming from the unit (but no fan). The unit would run for about a minute and turn off. 3 or 4 minutes later, the cycle would start again. I went so far as to set the thermostat to the lowest position and the selector switch to furnace (to maybe trick the system into only turning on the furnace) and plug the rig land line in. No luck. Compressor kicked on then off then on then ......... I then raised the temperature and the heater kicked on (with the compressor still running). When I went to disconnect the landline (a 12 gage extension cord), the socket was noticeably warm indicating I was pulling some serious current.

Two things to note. 1) Everything worked perfectly about two months ago then the rig was sitting idle until now. 2) this all happened with the thermostat is in the off position and the fan is set to auto.

Not sure if this is a thermostat issue, a relay issue, or ????? I would appreciate and insight on what to trouble shoot. Right now, I've set the "air" breaker to off to protect the system.
__________________

Robmawer is offline   Reply With Quote
Old 10-14-2018, 06:11 AM   #2
Head Rambler
 
Join Date: Mar 2008
Location: Southwest Alabama
Posts: 5,423
If you have the square looking Single Zone LCD Thermostat, you can try initializing it. If that doesn't work you'll probably have to replace it.

Quote:
• Make sure the Single Zone LCD thermostat is in the Off condition.
See page 4, “Quick Reference To Control Buttons”.
• Press the “+” button and, while holding it, also press and hold
the On/Off Mode button for three seconds. LCD will show ― ― .
Press the On/Off Mode button again to turn system off.
This completes the initialization.
__________________

__________________
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!
Bama Rambler is online now   Reply With Quote
Old 10-14-2018, 06:20 AM   #3
Senior Member
 
Join Date: Feb 2015
Posts: 613
Pull the red wire off the thermostat and see if it still does the same thing. If it does then most likely not the stat.
__________________
2019.5 Rockwood 2509S
Toddupton is online now   Reply With Quote
Old 10-14-2018, 06:28 AM   #4
NH Maple Maker
 
russhd1997's Avatar
 
Join Date: Aug 2017
Location: Loudon, New Hampshire
Posts: 259
I would start at the thermostat and fault trace further if that's not the issue. The puzzling part is that you can't hear a fan running on the A/C unit. Any time that the compressor is running a fan should also be running to pull air through the condenser. The air flow through the condenser keeps the high pressure in check.
__________________
Russ

2014 V Cross VIBE 822VRBS

2017 Silverado 1500 crew cab 4x4
russhd1997 is offline   Reply With Quote
Old 10-14-2018, 09:59 AM   #5
Junior Member
 
Join Date: Oct 2018
Posts: 6
Dometic A/C update

OK - I took Todd Uptons recommendation and removed the "red" wire (ID'd as 7.5v). When I turned the breaker back on, No change; same thing on top unit was running. I took a chance and removed the yellow wire from the thermostat (ID'd as Cool). As I removed it, I can hear a relay clicking in the "Stat". When I turned the breaker back on, silence. No A/C, pump, etc.

Is it same to assume, the problem is elsewhere (meaning not the thermostat)?

Also, does anyone see any issue with leaving the yellow (Cool) wire disconnected? We're going out in a few weeks for a weekend trip and short time RV service seems to be tougher to get here in So. Cal (meaning a 2-3 month waiting list for my local repair place). Seeing as we are into fall, the need for A/C is probably gone.
Robmawer is offline   Reply With Quote
Old 10-14-2018, 10:00 AM   #6
Junior Member
 
Join Date: Oct 2018
Posts: 6
BTW -thanks

Thanks to everyone who responded to my problem so quickly
Robmawer is offline   Reply With Quote
Old 10-14-2018, 01:11 PM   #7
Senior Member
 
Join Date: Jul 2012
Location: Orange Texas
Posts: 703
Send a message via MSN to Tiggerdad
Did you try to spin the fan to see if it's locked up or stiff. Your AC will continue to short cycle until the fan comes on.
__________________

2013 Crusader 330 MKS
2013 Chevrolet Silverado LT 2500 D/A
Tiggerdad is offline   Reply With Quote
Old 10-14-2018, 01:42 PM   #8
Senior Member
 
Join Date: Feb 2015
Posts: 613
Quote:
Originally Posted by Tiggerdad View Post
Did you try to spin the fan to see if it's locked up or stiff. Your AC will continue to short cycle until the fan comes on.
It shouldn’t if the thermostat is not calling for it.
__________________
2019.5 Rockwood 2509S
Toddupton is online now   Reply With Quote
Old 10-14-2018, 02:15 PM   #9
Senior Member
 
mkekflyers's Avatar
 
Join Date: Aug 2015
Location: Ft Myers FL
Posts: 193
Quote:
Originally Posted by Bama Rambler View Post
If you have the square looking Single Zone LCD Thermostat, you can try initializing it. If that doesn't work you'll probably have to replace it.
That cured some wired issues I had with one of mine. Kinda like a CNTRL+ALT+DEL on your PC...

Let us know if that works please...
__________________
2018 Georgetown 378 XL
2012 Ford Edge TOAD
Blue Ox & RVIBrake
2014 - 37; 2015 - 58; 2016 - 64;
2017 - 93, 2018 - 137
mkekflyers is offline   Reply With Quote
Old 10-14-2018, 02:15 PM   #10
Senior Member
 
Join Date: Jul 2012
Location: Orange Texas
Posts: 703
Send a message via MSN to Tiggerdad
Quote:
Originally Posted by Toddupton View Post
It shouldn’t if the thermostat is not calling for it.
While I agree there could be a number of issues and not related to whether the fan works or not BUT do we know whether or not the thermostat is calling for cooling? If it is, shouldn't it also call for the fan to run just prior to the compressor coming on?

I am confused why the compressor comes on when the OP plugs into AC. Is the thermostat on prior to plugging in?

Edit, I see where the OP did say the thermostat was off.
__________________

__________________

2013 Crusader 330 MKS
2013 Chevrolet Silverado LT 2500 D/A
Tiggerdad is offline   Reply With Quote
Reply

Tags
air conditioner

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Featured Campgrounds

Reviews provided by


Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 01:33 PM.