A/C starts, then kicks out

Hi all!
Just got back from a week long camping trip today and the A/C worked great until yesterday. Since it was nice and cool Thursday night, we turned it off but then yesterday afternoon decided to turn it back on. The fan would start running for a few seconds, then you could hear the A/C kick in. A few seconds later, you could hear the A/C kick out, in essence going back to fan-only mode. Has anyone experienced this in the past or have any ideas what may be going on here?

Thanks much!
Jeff

Two thoughts on that. Your power supply to the trailer is inadequate or the starting capacitor on the A/C is going bad. Both answers could be wrong.

Jeff H said:

Hi all!
Just got back from a week long camping trip today and the A/C worked great until yesterday. Since it was nice and cool Thursday night, we turned it off but then yesterday afternoon decided to turn it back on. The fan would start running for a few seconds, then you could hear the A/C kick in. A few seconds later, you could here the A/C kick out, in essence going back to fan-only mode. Has anyone experienced this in the past or have any ideas what may be going on here?

Thanks much!
Jeff

Click to expand...

Jeff,

I am not an AC person so I ran your question through my son-in-law who has over 30 years in the AC/Heating business. His first thought is in agreement with what RichR stated, the starting capacitor. In searching the Internet, I found this bit of information:

" Start and run capacitors are normally used in AC motors to aid in starting and running efficiency. Both capacitors are wired in series with the start winding of the motor. The reason they are not both called start capacitors is that the start capacitor gives the motor more torque to overcome the fact that it is at standstill, and then automatically disconnects itself from the circuit. The run capacitor gives the motor better running efficiency and remains part of the circuit, it is therefore called the run capacitor".

Based on this information and the way you described your AC unit, I would say the start capacitor is starting up okay but either it is not getting the rpm speed up high enough to hand it off to the 'run' capacitor or the run capacitor is shot. If I'm not mistaken the start and run capacitors are combined into a single long, round cylindrical capacitor mounted inside the unit. I would think you may need a new capacitor.

His other comment was your compressor may be stuck [frozen].

Regardless, unless you are familiar with the high voltage stored within capacitors even after the AC has been removed, and know how to discharge them correctly, you are subject to get a terrific shock that can cause you physical harm so his recommendation is this is not a DIY job and you should get a professional to check and/or replace the capacitor.



I hope this helps.

Jcurtis95

jcurtis95 said:

Regardless, unless you are familiar with the high voltage stored within capacitors even after the AC has been removed, and know how to discharge them correctly, you are subject to get a terrific shock that can cause you physical harm so his recommendation is this is not a DIY job and you should get a professional to check and/or replace the capacitor.

Click to expand...

While in college, I worked part-time at a friend's British motorcycle shop. We kept in stock capacitors that were used to eliminate the battery from the charging system on the bikes. We often would charge a few capacitors, and put them in a parts bin on a high shelf. Then we would ask a newbie to go fetch one. Invariably the person would reach up into the bin and get shocked.

Thanks for the info, Rich and Jerry; please thank your son-in-law too, Jerry! I think it's time to have a professional take a look at it.
Not sure what to say about tricking the newbies, Raul. But most of us have seen both sides of that situation in some way, shape or form over the years!

Jeff

Update

Just got the bad news after having the A/C looked at: Start-up and run capacitors are shot, start-up motor shot and accumulator smells burned. The solution is to replace the unit at a cost of about $1500....ouch!! The dealer said this is a high-end A/C and that he has not seen this before. Not sure when or if the A/C will be replaced, but it won't be this fall. I am going to let Dometic know that I am not happy about the A/C failing after only 7 seasons (bought camper new in July of 2007) of camping. The A/C has maybe been used 10-12 days per year, which is not a very impressive lifespan.

Jeff

Jeff H said:

Just got the bad news after having the A/C looked at: Start-up and run capacitors are shot, start-up motor shot and accumulator smells burned. The solution is to replace the unit at a cost of about $1500....ouch!! The dealer said this is a high-end A/C and that he has not seen this before. Not sure when or if the A/C will be replaced, but it won't be this fall. I am going to let Dometic know that I am not happy about the A/C failing after only 7 seasons (bought camper new in July of 2007) of camping. The A/C has maybe been used 10-12 days per year, which is not a very impressive lifespan.

Jeff

Click to expand...

Jeff,

I am running this prognosis through my son-in-law. It doe not sound just quite right to me. We'll see what he says.

Jcurtis95

Thanks for the extra inputs, Jerry! I do need to clarify part of my earlier post. The written info states that the start relay is shorted (not the start-up motor being shot) as I thought the counter guy said.

Jeff

I could only hope this was your problem also. Same scenario for us, worked great then wouldn't, just the fan. Our first step my husband got a new battery, because the other one was 13 years old (WOW)!! wasn't it, then we read on here some. Long story short it ended up being the ground wire in our battery compartment, he bumped it when he replaced the battery the air kicked on momentarily might be worth a check. Good Luck!!

Jeff H said:

Thanks for the extra inputs, Jerry! I do need to clarify part of my earlier post. The written info states that the start relay is shorted (not the start-up motor being shot) as I thought the counter guy said.

Jeff

Click to expand...

Jeff,

I don't know if this will help but here is the response from my son-in-law:

"I dont like the way this sounds.Relays,capacitors,and small parts are very cheap and easy to replace.Acid smells from the freon system can be a bad sign.
If the compressor was "locked up,Shorted out,Grounded out" I would see the need for a complete new system. I think he needs to find another repair tech".

Jeff, I realize that when a technician checks your AC unit, you are going to be charged a fee. I just do not like to have a 'change-out' technician look at an AC unit that he calls "a high-end AC" with the purpose of selling you a new unit rather that try and repair the old unit. Did you have a credible AC tech look at your unit? If you don't have personal knowledge of the integrity of the individual or the company he works for, you might want to get a second opinion. I would suggest checking around with friends or family that may recommend an up-front kind of technician that will try to repair first rather than be chomping at the bits to try and sell you a new one. If you know of a good RV repairman, if it were me, I would have someone else look at it and if they both agree that replacement is the only way, then go from there.

The rooftop AC units on RV's are pretty much the same. Before I would buy a new one, I would check around and consider buying a used one. If you have to replace your unit, check out eBay for RV AC units. Here are examples of what is available in new AC units:

RV/Air Conditioner | eBay

Most of these are brand new units for a lot less that $1500. Hope this helps.

jcurtis95

Jeff H said:

Just got the bad news after having the A/C looked at: Start-up and run capacitors are shot, start-up motor shot and accumulator smells burned. The solution is to replace the unit at a cost of about $1500....ouch!! The dealer said this is a high-end A/C and that he has not seen this before. Not sure when or if the A/C will be replaced, but it won't be this fall. I am going to let Dometic know that I am not happy about the A/C failing after only 7 seasons (bought camper new in July of 2007) of camping. The A/C has maybe been used 10-12 days per year, which is not a very impressive lifespan.

Jeff

Click to expand...

I think you should get a second opinion, these A/C units are not high end units. High end units have 2 compressors and computer boards. It sounds like the dealer didn't have a high enough caliber specialised a/c service tech. So its easier and cheaper for the dealer just to replace the unit.
The only reason to replace the unit is if the compressor is burnt-out, because the parts and labor becomes higher than the units cost. To check, you OHM out the compressor. Did the dealer do this or just use his nose? Get the part #'s off the capacitors and replace yourself,there $20 a piece. The factory won't help, its out of warnitty. They will have you get a qualitified service tech to look at it.The $1500 for a replacement is to high, get the model number on shop around on the net.

What's the model# of the A/C unit, it's located behind the air filter on the inside. I have an 06 hi-lo, I work in the HVAC trade and I'll look up the wiring diagram/system design.

Thanks for the insights, Jerry and Les! I was surprised to hear the shop say replacement vs. repair, though. Even if it cost about $500 to repair that would be much less than what I was quoted: New Penguin A/C unit cost would be ~$935, heat strip would be another ~$160 (I would not bother since I have never used it) and about $450 for installation.
Unfortunately, I don't know of a good RV repairman and there are not many options for repair in my area that are less than a one hour drive.
Thanks for the offer to look up the wiring diagram/system design, Les! The model number for mine is: 600315.331.

Jeff

Jeff H said:

Thanks for the insights, Jerry and Les! I was surprised to hear the shop say replacement vs. repair, though. Even if it cost about $500 to repair that would be much less than what I was quoted: New Penguin A/C unit cost would be ~$935, heat strip would be another ~$160 (I would not bother since I have never used it) and about $450 for installation.
Unfortunately, I don't know of a good RV repairman and there are not many options for repair in my area that are less than a one hour drive.
Thanks for the offer to look up the wiring diagram/system design, Les! The model number for mine is: 600315.331.

Jeff

Click to expand...

Jeff,

In case you do not have the manual, I found one online here:

http://manuals.adventurerv.net/Dometic-Air-Conditioner-6003-3309032.005.pdf

I also found several Penguin AC units on eBay :

penguin RV/Air Conditioner | eBay

If you determine you have a defective unit, you may consider buying one and installing it yourself. That would save you $800 to $900 and it is not that difficult to change out a roof unit. You would need some help getting it in onto the roof and you probably would not want [2] people on the roof at the same time. Installation instructions are in the manual and your major concern would be the dimensions of the replacement unit.

When we lived in Colorado, we bought a Toy Hauler. The height of the AC unit exceeded my barn's 12' garage door height; so, whenever we placed the unit in for the winter, I would have to remove the AC unit and move it to a lower section on the inclined roof before I could put it inside the barn. It was not a difficult task and I did it by myself.

Just something for you to consider. Good Luck.

jcurtis95

air conditioner problems

JCURTIS95, Outstanding job with air conditioning information. Retirement gives you the time to help a HiLo owner.

Thanks for the manual link and insight on replacing the unit myself, Jerry! I am not sure what my next step will be but I have some time to weigh my options.

Jeff