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KxRdr
07-10-2012, 01:14 AM
My A/C runs on "fan" but when switch to A/C it shuts off completely. Ideas?
I pulled the cover off the A/C and checked the capacitors- they look good and none of them smell burnt-The A/C was also doing this on our last trip.
Maybe I should replace the capacitors anyway???

truggyboy
07-10-2012, 01:22 AM
how long has it been since you used it. The last time mine did that the compressor was stuck. I was able to get it to move and it has been fine ever since. think I moved the shaft using some pliers or something like that. Had to do it from the top with the cover off. Just a thought.

jws
07-10-2012, 01:40 AM
Mine has locked up too.....

jws
07-10-2012, 02:03 AM
My A/C runs on "fan" but when switch to A/C it shuts off completely. Ideas?
I pulled the cover off the A/C and checked the capacitors- they look good and none of them smell burnt-The A/C was also doing this on our last trip.
Maybe I should replace the capacitors anyway???

Do you run the AC at home while plugged into the house???

thmTerry
07-10-2012, 03:01 AM
mine was a broken wire to the thermostat

ssduane
07-10-2012, 03:29 AM
probably the compr overload. the contacts get "burnt" and will not allow sufficient power to get through them to allow for start. I can give you some info on how to check capicators, overloads and the windings in the compressor, if you want.

Also, fan is wired into 12v, at least mine is, AC comp, into 120 so that is why you have fan but no AC.

KxRdr
07-10-2012, 04:23 AM
Do you run the AC at home while plugged into the house???

I don't have a 30 or 50 amp plug at home to run the A/C. We plug in 110volt house plug to charge batteries and to cool the fridge before trips. This A/C problem is acting the same whether it be shore power or genny based on our last trip to Santa Cruz.

KxRdr
07-10-2012, 04:25 AM
how long has it been since you used it. The last time mine did that the compressor was stuck. I was able to get it to move and it has been fine ever since. think I moved the shaft using some pliers or something like that. Had to do it from the top with the cover off. Just a thought.

The fan runs but A/C doesn't kick on when swithced to A/C selection.

KxRdr
07-10-2012, 04:32 AM
probably the compr overload. the contacts get "burnt" and will not allow sufficient power to get through them to allow for start. I can give you some info on how to check capicators, overloads and the windings in the compressor, if you want.

Also, fan is wired into 12v, at least mine is, AC comp, into 120 so that is why you have fan but no AC.

Make the most sense so far...The capacitors don't smell bad. It may be a circuit breaker- even a broken wire like Terry suggests. There is an additonal circuit board breaker where shore power hooks up behind a panel on our trailer . I've never seen it but it's the breaker that clicks on when you run the genny- something else to poke at.

I appreciate all your help

Steve

truggyboy
07-10-2012, 05:04 AM
The fan runs but A/C doesn't kick on when swithced to A/C selection.

That's exactly what mine did. That's why I said that. The fan is 12 volts and the ac compressor it 110 ac

I would check to make sure the compressor turns.

2BH
07-10-2012, 12:50 PM
My A/C runs on "fan" but when switch to A/C it shuts off completely. Ideas?
I pulled the cover off the A/C and checked the capacitors- they look good and none of them smell burnt-The A/C was also doing this on our last trip.
Maybe I should replace the capacitors anyway???

Did you check for any telephone cable wedged between the roof and A/C?:ph43r:


...just sayin':rolleyes:

ssduane
07-10-2012, 01:31 PM
if you pull the terminals off the compressor, there should be three wires/plug connected, they are labeled S-start, R-run and C-common. there should be an overload in line with the C terminal, a small round piece with a wire and plug. Looks like this possibly http://1.bp.blogspot.com/_MtPShF3aUKw/TFVdelofctI/AAAAAAAAAYE/os4gnkE0-x8/s1600/Overload+AC.jpgyou can check continuity from terminal to terminal, if it has flow through it, it should attempt to start. Then also with everything hooked up try to start with a clamp on meter and see what amperage draw on the C lead is.

Carefull of the capacitor, they are charged and need to be discharged to test. youtube has some videos.

For the compressor, the three terminals, you can check resistance from lead to lead, C-R resistance and C-S resistance should equal S-R resistance. if C-R is 3.4 ohms, and C-S is 6.7 ohms, S-R should be around 10.1 ohms. This will tell you if the windings are good.

Big Buford
07-10-2012, 01:40 PM
Let me know if you need an extra hand steve off at 2:30

Nayther
07-10-2012, 03:55 PM
Let me clear up a couple of things. The entire A/C unit is 120 volts, there is a transformer that powers the thermostat. Have you ever turned on just the fan without shore power or the gennie running? You said the fan runs but when you get a "call for cooling" it all goes off, would suspect a breaker is tripping but maybe not. Check the voltage when the compressor tries to start, if it's locked up you will see a BIG dip in voltage as the amperage spikes.

Also you cannot "break the compressor loose" with a pair of pliers, it is a sealed compressor (hermetic compressor is the proper term).

I would bet the compressor is locked up or "stuck". If it's "stuck" you may be able to break it free with a new and/or larger start capacitor, kind of like an extra nudge to get it going, we use something called a "hard start kit" in larger systems, they might make one for your A/C but not sure.

KxRdr
07-10-2012, 04:13 PM
Did you check for any telephone cable wedged between the roof and A/C?:ph43r:


...just sayin':rolleyes:

Scootttiieeeee!!!!!! Stop it! :ass::bs::vik:

Now then... moving on...

KxRdr
07-10-2012, 04:15 PM
Let me clear up a couple of things. The entire A/C unit is 120 volts, there is a transformer that powers the thermostat. Have you ever turned on just the fan without shore power or the gennie running? You said the fan runs but when you get a "call for cooling" it all goes off, would suspect a breaker is tripping but maybe not. Check the voltage when the compressor tries to start, if it's locked up you will see a BIG dip in voltage as the amperage spikes.

Also you cannot "break the compressor loose" with a pair of pliers, it is a sealed compressor (hermetic compressor is the proper term).

I would bet the compressor is locked up or "stuck". If it's "stuck" you may be able to break it free with a new and/or larger start capacitor, kind of like an extra nudge to get it going, we use something called a "hard start kit" in larger systems, they might make one for your A/C but not sure.

The system does work just not every time I switch it on to A/C
For under a hundy I can replace all 3 capacitors on the A/C plus Grainger can test each capacitor at their facility to see if they're good.

KxRdr
07-10-2012, 04:18 PM
Let me know if you need an extra hand steve off at 2:30

Coolio Mark. I'll call If I get stumped. I was trying to fix this before this weekend. I still have the front A/C. I'm riding a dual sport ride at Lake Isabella this weekend. I still have time to resolve this issue before Utah.

KxRdr
07-10-2012, 04:20 PM
Scootttiieeeee!!!!!! Stop it! :ass::bs::vik:

Now then... moving on...

O.K. post a pic... Timing would be appropriate...

jws
07-10-2012, 07:22 PM
we use something called a "hard start kit" in larger systems, they might make one for your A/C but not sure.

Not sure if the one I have is to big for your A/C Steve but your welcome to give it a try - It might jump start your unit and free it up at least:vib::vib::vib::vib::vib:

http://i183.photobucket.com/albums/x313/jws8402/IMG_0219.jpg

http://i183.photobucket.com/albums/x313/jws8402/IMG_0218.jpg

jws
07-10-2012, 07:54 PM
Looks like it would work. I remember we had a discussion on here about running our Trailer A/C off a Honda 2000........

http://www.modmyrv.com/2009/05/27/rv-air-conditioner-hard-start-capacitor

:vib::vib::vib::vib::vib::vib::vib::vib::vib:



Mod Description:

Ever try to start your A/C on a hot day at high altitude with a generator that is supposedly rated to handle the A/C’s starting requirements? The generator struggles, goes in to overload, or just plain stalls because it cannot supply the current demands of the A/C’s motor fast enough. Stories abound that many are able to start their RV air conditioners using a Honda EU2000 or Yamaha 2400i, or other small wattage generator. How are they able to do this while others can’t? Chances are they have modded their RV’s air conditioner with a hard start capacitor.

Mod Difficulty:
Supco SPP6E A/C hard start capacitor
Example Dometic Brisk Air wiring diagram
Dometic Brisk Air wiring diagram underneath A/C intake grill
Dometic A/C outside cover - notice all the screws!
Located in the front right of the A/C unit, the utility box contains start and run capacitors
Wiring diagram for A/C compressor motor and blower motor
Close up of capacitors - the shiny one is the motor run capacitor and the black one is the motor starting capacitor
The starting cap is 43-53 uF while the Supco is 88 to 106 uF - theis means more starting power!AC
Typical OEM motor starting capacitor - same as the one shown in the utility box

A typical RV air conditioner will have both a compressor motor starting capacitor and blower motor run capacitor, since they are generally of the Capacitor Start Induction Run (CSIR) type. The other less common type is the Permanent Split Capacitor (PSC) arrangement, which is not usually used in an RV application. Even if your A/C has a starting capacitor, you can still benefit from this mod. Most stock starting capacitors are a bit undersized and replacing it with a larger boost capacitor can help, especially if you are trying to start your A/C using a small generator. For those whose A/C has no starting capacitor from the factory, this mod will really help with compressor motor startup current demands.

The recommended (and most popular) starting capacitor for a 13,500-15,000 BTU RV A/C is the Supco SPP6E boost capacitor. This capacitor has an electronic disconnect and provides about twice the current boosting power as the factory start capacitor. If your A/C doesn’t have a seperate boost capacitor as shown in the pictures above, it’s likely that the run capacitor doubles as the boost capacitor, and also has a Positive Temperature Coefficient Relay (PTCR), a fancy term for the way the capacitor is removed from the circuit once the motor starts. The PTCR is prone to failure which can cause the capacitor to fail, and thus make the compresor motor startup current demands very high or not able start at all. This is the reason Supco makes an electronic version of the PTCR. It is much more reliable and is integrated in to the capacitor packaging.

So now that you know more than you ever wanted to know about starting capacitors, how do you mod your RV with one? It’s actually pretty easy. The hardest part is getting on the roof of your RV. To install the capacitor, you must remove the shroud covering the A/C internals. But first, be sure to disconnect any electrical power from the RV. You will be working with AC wiring which, if energized, can kill you. If in doubt, consult a qualified electrician to either assist or do the job for you. Don’t try this mod if you are unsure!

Start by removing the A/C cover. These are typically secured with many screws so use a battery-powered screw gun unless you prefer a hand workout. Locate the utility box containing the motor and/or starting capacitor. On a Dometic brand A/C, it’s located near the top right corner and should have a wiring diagram on the outside of it. Remove the screws holding the cover on, then remove the cover. There should be two screws (refer to the pictures above).

After the cover is removed, you should see either one or two cylindrical looking parts with several wires running to them. If there are two, then the one that is usually black and totally round (not oval-shaped which is the blower motor run capacitor) is the factory starting capacitor. it should have two wires coming from it. If this is the case, simply disconnect the wires leading from the starting capacitor and remove it. The Supco capacitor will be a direct replacement. Connect the two wires from the new capacitor to where the old capacitor wiring was connected.

If your A/C does not have a starting capacitor, refer to the Supco wiring recommendations that came with your boost capacitor for the various types of capacitor/wiring configurations. Generally though, the new boost capacitor will be wired in parallel, or “piggy-back”, to the motor run capacitor using the supplied jumper terminals. Again, if in doubt, seek the advice of a professional electrican or HVAC technician.

You thought there was more to this mod? Nope. It’s really that simple to do. Not only will your A/C start up easier while on shore power without popping the breaker, you stand a much better chance of starting and running the A/C using a smaller generator. If you have questions, feel free to comment below and we will do our best to get you an answer quickly!

ssduane
07-10-2012, 07:56 PM
The system does work just not every time I switch it on to A/C
For under a hundy I can replace all 3 capacitors on the A/C plus Grainger can test each capacitor at their facility to see if they're good.

So the compressor does come on sometimes? If thats the case I would assume overload going bad.

jws
07-10-2012, 08:00 PM
Here is a thread that says dont use the spp6e use the one I have spp6....

http://www.rv.net/forum/Index.cfm/fuseaction/thread/tid/25258173/srt/pa/pging/1/page/1.cfm

:vib::vib::vib::vib::vib::vib::vib::vib::vib:

Nayther
07-10-2012, 08:47 PM
that's the "hard start" kit I was referring to and since you say it runs occasionally might be a good bet that you have a weak start capacitor and this would help, then again a good OEM size cap. would also fix it.

What DS are you riding in Isabella this weekend, was not aware of one. I rode the Team Dual Dogs a while back, lots of great stuff up there and it you get up high it's much cooler.

KxRdr
07-10-2012, 09:45 PM
that's the "hard start" kit I was referring to and since you say it runs occasionally might be a good bet that you have a weak start capacitor and this would help, then again a good OEM size cap. would also fix it.

What DS are you riding in Isabella this weekend, was not aware of one. I rode the Team Dual Dogs a while back, lots of great stuff up there and it you get up high it's much cooler.

Mike Thompsons Sante Fe Springs says to start with the switch on the wall... go figure.

One of the members with TWMC posted a ride from Lake Isabella to Sherman Pass Road. Supposed to be about 140 miles. Probably about 8-10 riders total.
Starts at Cannell Meadow Trail in Kernville.

Nayther
07-10-2012, 09:50 PM
Mike Thompsons Sante Fe Springs says to start with the switch on the wall... go figure.

One of the members with TWMC posted a ride from Lake Isabella to Sherman Pass Road. Supposed to be about 140 miles. Probably about 8-10 riders total.
Starts at Cannell Meadow Trail in Kernville.

Rode Cannel meadow last year, fun first section of switch backs up the hill, then transitions to a jeep trail until it hits Sherman Pass (we turned around at the top as it was getting late and it was too far to go via Sherman Pass). Hope you're starting early because the first 10 miles or so will be HOT later in the morning.

Are you in TWMC? If so I'm hoping to make the Ghost Rider this year, it's right after our G.P. so sometimes tough but it's on my bucket list for this year's races.

KxRdr
07-10-2012, 09:58 PM
Rode Cannel meadow last year, fun first section of switch backs up the hill, then transitions to a jeep trail until it hits Sherman Pass (we turned around at the top as it was getting late and it was too far to go via Sherman Pass). Hope you're starting early because the first 10 miles or so will be HOT later in the morning.

Are you in TWMC? If so I'm hoping to make the Ghost Rider this year, it's right after our G.P. so sometimes tough but it's on my bucket list for this year's races.
7 am start. Sounds like we're doing a similar ride. How did your fuel hold up? How much fuel did you use. Yes, I'm with TWMC and next year TWMC is supposedly doing the Oct. Race and then switching to April for future years. So that's 2 Ghostrider races in one year ( edit to say riding season 2012 and April 2013 ) from TWMC. I've haven't missed a TWMC Ghostrider race in 20 plus years but next year may be my first if this group can pull together a ride to Primm in October.

Nayther
07-10-2012, 10:58 PM
I might be able to get 140 out of a single tank (Clarke on 450x) but that would be pushing it. Except it's pretty slow riding going up, so not more than about 1/2 throttle and once you get to the top I assume you'll take the jeep road to Sherman and slab it back down, not much of any throttle there. I like to keep it to 100 miles max to be safe though but I've done 120 on the stock tank.

the Primm ride the one Crawford's working on?

KxRdr
07-11-2012, 04:27 AM
The Primm ride is put on by this group. I can get 135 miles riding 4th 5th gear. Looks like i may need to tote along some extra fuel.

KxRdr
07-11-2012, 04:35 AM
Replacing capacitors made no change. I'm going with a new thermostat control switch tomorrow.( operating switch on the wall ) Those have to be cheap

ssduane
07-11-2012, 04:50 AM
yes, the cheap ones are cheap, can always check to see power in and power out of the thermo switch works. or you can check the overload.



Just saying.

jws
07-11-2012, 05:59 AM
Replacing capacitors made no change. I'm going with a new thermostat control switch tomorrow.( operating switch on the wall ) Those have to be cheap

I replaced the one ony ww..... I also have a spare thermostat that Phil gave me a few years back your welcome to it ...

KxRdr
07-11-2012, 08:58 PM
Thanks Jeff,
I bought a new controller and installed it. If I start up my genny, wait for the 110v to kick on, turn on A/C, it turns on. Works fine. If I push the thermosat to max hot it turns off- like its supposed to. If I then push the thermostat down to say 65 deg. for the A/C to turn back on it takes about 2 minutes and then it turns on. Does this sound about right? It doesn't just kick back on because I moved the thermostat from 90 deg. back to 65 degrees- It kicks back on after about 2 minutes.

thmTerry
07-11-2012, 09:14 PM
it takes time to reset..working normal

Nayther
07-11-2012, 09:19 PM
If you put in a new digital thermostat there is a built in time delay so that would be normal. You don't want to bang it on and off, the pressures in the system need to equalize. Still don't understand some of the symptoms you described but if it works, then it's all good. Test it again and let it pull down to temperature and cycle off, then let it go come back on again on it's own. If that checks out then I think you've got it licked.

Have a good ride in Isabella!

jws
07-11-2012, 09:28 PM
it takes time to reset..working normal

Mines the same way:vib:

KxRdr
07-11-2012, 10:29 PM
Cool. I think I can put this issue to rest.

jws
07-11-2012, 10:43 PM
Cool. I think I can put this issue to rest.

:strip::strip::strip::strip::strip:

Coribdx
07-12-2012, 01:02 AM
Wait.... Mr. Color blind had to have ME come tell him which wires to connect..... being color blind must suck....

Coribdx
07-12-2012, 01:35 AM
Is that red, green or gray?

ssduane
07-12-2012, 03:07 AM
yes, most have an anti-cycle to prevent excessive wear on the compressor from starting/stopping, pressure equilization. So, did it not work before on the genny? Or when plugged into shore power?