March 3, 2025

RV Living

On The Road Again With RV Living

RV Forum

We have many new features on our forum, RV-Living forum has information on just about any topic.
Check Out RV Forum Today

Please Re-Register To Access All Our Forums New Features on RV-Living Forum

 

Post all your RV questions or comments on RV Forum

RV Forum

A/C compressor trie...
 
Notifications
Clear all

A/C compressor tries to start just keeps cycling

12 Posts
1 Users
0 Reactions
83 Views
(@Ed Russell)
New Member
Joined: 5 years ago
Posts: 1
 

I have 2 rooftop duo-therm ac's with heat pumps. the living room ac was working fine then the compressor started shutting down and restarting for maybe 2 to 3 seconds each time and would cycle on and off. The fan stayed on throughout. It has been 90 with high humidity so I turned it off for the night. This morning when I tried to restart the ac it took about 2 - 2 1/2 minutes for the fan to come on (normal start) but again the compressor would try to start, I could here it bump on but shut back off, after a couple times of this I shut it off again waited a while and tried it again same results. I pulled the capacitor check it with an analog volt meter. it bounced to zero then back at each side, and it had no visual damage. Any Ideas??


   
ReplyQuote
(@I'mdonewiththis forum)
New Member
Joined: 5 years ago
Posts: 1
 

First of all, Welcome! Sounds to me like your compressor is about dead. Something is failing inside the compressor and it is pulling way to much power to try to start. It probably shut down from the overload tripping and wouldn't restart due to current draw. I don't suppose you checked to see if you could put your hand on the compressor when it first acted up? It was probably quite hot.......


   
ReplyQuote
(@Ranger Smith)
New Member
Joined: 5 years ago
Posts: 1
 

It sounds like a bad capacitor. You can really only check if compressor is pulling too much with a clamp on amp meter. I would go and buy the cap for $15 to 20 bucks and try that. 


   
ReplyQuote
(@Ed Russell)
New Member
Joined: 5 years ago
Posts: 1
 

No I didn't. I rest my thermostat checked the lines in the unit to see if clean.. My wife said that when she turned it on earlier it sounded like it started hard. is there anything further I can check? I did checked the 3 amp fuse,good, didn't see loose wires either..


   
ReplyQuote
(@Ed Russell)
New Member
Joined: 5 years ago
Posts: 1
 
  On 11/1/2019 at 8:40 AM, Ranger Smith said:

It sounds like a bad capacitor. You can really only check if compressor is pulling too much with a clamp on amp meter. I would go and buy the cap for $15 to 20 bucks and try that. 

I need a 50+15 and have a local shop looking for one. I wasn't able to find one on amazon, Graingers. ebay,..  Was hoping I missed something on the board.

 


   
ReplyQuote
 D&J
(@D&J)
New Member
Joined: 5 years ago
Posts: 1
 
  On 11/1/2019 at 8:22 AM, Ed Russell said:

I have 2 rooftop duo-therm ac's with heat pumps. the living room ac was working fine then the compressor started shutting down and restarting for maybe 2 to 3 seconds each time and would cycle on and off. The fan stayed on throughout. It has been 90 with high humidity so I turned it off for the night. This morning when I tried to restart the ac it took about 2 - 2 1/2 minutes for the fan to come on (normal start) but again the compressor would try to start, I could here it bump on but shut back off, after a couple times of this I shut it off again waited a while and tried it again same results. I pulled the capacitor check it with an analog volt meter. it bounced to zero then back at each side, and it had no visual damage. Any Ideas??

Sounds like you tested the run cap, does it have a start cap and relay. It sounds like the start cap isn't kicking in.

Denny 


   
ReplyQuote
(@Ronbo)
New Member
Joined: 5 years ago
Posts: 1
 

You can try adding a hard start kit to your unit. I just ordered one today for $8 on amazon


   
ReplyQuote
(@Big Greg)
New Member
Joined: 5 years ago
Posts: 1
 

I have had this problem twice, the fan comes on and the compressor starts but stops in 3 or 4 seconds.  I replaced the start capacitor and PTCR to fix the problem.  You can purchase a kit from RV dealers or online for about $30.       Greg


   
ReplyQuote
(@Ranger Smith)
New Member
Joined: 5 years ago
Posts: 1
 
  On 11/1/2019 at 8:50 AM, Ed Russell said:

I need a 50+15 and have a local shop looking for one. I wasn't able to find one on amazon, Graingers. ebay,..  Was hoping I missed something on the board.

 

50 + 15 is an odd one. Who makes the AC unit. I usually just replace them with a 35/5 at 370 volts and that is fine.


   
ReplyQuote
 D&J
(@D&J)
New Member
Joined: 5 years ago
Posts: 1
 
  On 11/1/2019 at 8:50 AM, Ed Russell said:

I need a 50+15 and have a local shop looking for one. I wasn't able to find one on amazon, Graingers. ebay,..  Was hoping I missed something on the board.

 

That is the run cap for the compessor and fan, go back into the box and look for a single smaller cap that only has leads and that will be the start cap and check it.

Denny


Edited November 1 by D&J


   
ReplyQuote
(@Ed Russell)
New Member
Joined: 5 years ago
Posts: 1
 
  On 11/1/2019 at 3:23 PM, Ranger Smith said:

50 + 15 is an odd one. Who makes the AC unit. I usually just replace them with a 35/5 at 370 volts and that is fine.

Duo Therm by Dometic. 


   
ReplyQuote
(@Ed Russell)
New Member
Joined: 5 years ago
Posts: 1
 

thank you all for the advice, I'll let you know my results.

 


   
ReplyQuote

Leave a reply

Author Name

Author Email

Title *

Maximum allowed file size is 10MB

 
Preview 0 Revisions Saved
Share: