AC Breakers

Topic: AC Breakers (Read 980 times) previous topic - next topic

AC Breakers

April 18, 2022, 12:39:47 pm

Can anyone advise if there are other breakers for the 2 AC units besides the ones at the foot of the bed, and if so where are they?

Re: AC Breakers

Reply #1 – April 18, 2022, 12:46:41 pm

I would say that's it. There wouldn't be any reason for more.

Re: AC Breakers

Reply #2 – April 18, 2022, 01:15:39 pm

The 12VDC control voltage comes off a self resetting breaker in the dash behind the kick panel in front of the passengers seat.

Mike

Re: AC Breakers

Reply #3 – April 18, 2022, 01:28:24 pm

Ok...I am just doing some investigation about why my CC2 thermostat (4 button) does not show zone 2 and the rear AC does not work. When I disconnect the rear AC from the front, the front AC works (on gen power)
I have discussed this with many on site here.
This happened last summer, and NOW I suspect it is because I started both AC units while on 15 amp power and
may have "browned" out my rear AC (

?) Is this possible ?? My AC units are the 620315.321 Duo Therm Units
-I have purchased the 5 button upgrade kit including both control boards, but have not installed it yet, due to
me troubleshooting totally before installation of the unit.
-I have checked the data line between the AC units and ran an outside cord between to confirm it was not a cable.
So, I am trying to trouble shoot everything before I pay the big bucks to have someone look at it.

Re: AC Breakers

Reply #4 – April 18, 2022, 01:35:15 pm

Quote from: dicksop – April 18, 2022, 01:28:24 pm

Ok...I am just doing some investigation about why my CC2 thermostat (4 button) does not show zone 2 and the rear AC does not work.

That sounds like someone has messed with the dip switches up in the rear A/C unit and the Tstat don't know that you have a rear A/C unit.

Mike

Re: AC Breakers

Reply #5 – April 18, 2022, 03:04:42 pm

If you had only 15a going to coach and tried both AC's the breaker that is outside the coach that is connected to the outlet you were plugged into would have tripped before you damaged the unit due to brown out. But, never say never.

Re: AC Breakers

Reply #6 – April 18, 2022, 03:39:25 pm

Turbojack
Are you talking about the breakers at the foot of the bed or the front of the passenger feet?

Re: AC Breakers

Reply #7 – April 18, 2022, 05:23:19 pm

It would/should have tripped the 15 amp breaker that fed the plug where your RV was/is plugged in. If it was to trip one of the breakers at the foot of the bed that circuit would have been overloaded, one A/C unit per breaker. This would have no effect on the DC voltage breaker that is in the dash.

Mike

Re: AC Breakers

Reply #8 – April 18, 2022, 05:43:51 pm

What Mike said!

Each AC unit has a dedicated 120V circuit going to the breaker box at the bed. The AC's need 12DC in order to operate the control of the AC's The front AC has a circuit board that has a phone wire going to the thermostat. There should be 12 V DC at the front Circuit board which you should have since the front one works. There should also be 12VDC to the rear circuit board. Put a volt meter there and check to make sure you have 12 volts DC.

If everything has power the first thing I would do is kill the power going to the circuit boards, wait a few minutes and then reapply power. When it boots back up that might fix the problem of not seeing the rear AC unit.

Re: AC Breakers

Reply #9 – April 18, 2022, 05:46:17 pm

Quote from: dicksop – April 18, 2022, 01:28:24 pm

-I have checked the data line between the AC units and ran an outside cord between to confirm it was not a cable.
So, I am trying to trouble shoot everything before I pay the big bucks to have someone look at it.

You might verify that the data cable you tried is pinned out the same as the existing one. Not all cables are pinned the same.

Re: AC Breakers

Reply #10 – April 18, 2022, 06:45:23 pm

So can I kill the power to the breaker boards by turning off the salesman switch. Sorry, not as electrical a guy as I thought!! Open up the front passenger panel and located(I think) the ac breaker. But it is only one breaker...I suspect for both units?

Re: AC Breakers

Reply #11 – April 18, 2022, 08:24:34 pm

Quote from: dicksop – April 18, 2022, 06:45:23 pm

1. So can I kill the power to the breaker boards by turning off the salesman switch.
2.Sorry, not as electrical a guy as I thought!!
3. Open up the front passenger panel and located(I think) the ac breaker.
4. But it is only one breaker...I suspect for both units?

1. No. that buss that has about 4 breakers are fed all the time from/through a manual reset breaker in the basement behind the fiberglass cover. IIRC that is called the dash memory buss. Seems like the breaker is the 2nd or 3rd one from the bottom on the left side of those breakers in the basement.
2. This is the steeep learning curve all of us tinkers have been through. You are doing fine just don't be afraid to ask.
3. On that buss it seems like you need to look for breaker 51, 52 or 53 but these are auto reset.
3a. Your choice is to either take off the wire on on the breaker listed in #3 or trip the one in the basement that feeds this buss in #1
4. Yes

Mike

On edit: The IT department head run down an electronic print B-2197 that should be close for your coach and it list breaker #52 feeds the 2 AC units with 12vdc. BUT double check your prints to be sure.

Re: AC Breakers

Reply #12 – April 19, 2022, 12:13:57 am

Mike
I was fiddling around with the wires( phone cables ) again and now the thermostat does not light up or function at all,nor either AC. I did find the schematic 2197 and found breaker 52 on it which says AC and steps so I will try that tomorrow
So.... If that works to light up the thermostat is there any value in trying the 5 button upgrade kit I have?? This is frustrating the crap out of me and I really don't want or spend big coach bucks at arc repair shop!!!

Re: AC Breakers

Reply #13 – April 19, 2022, 06:16:48 am

Peter,

With you fiddling with the wire and losing power, it sure sounds like you have a bad spot in the phone cable or cable end. Until you find out why you are losing power to the Tstat there ain't no need to change out to another Tstat. There is no need to pay a shop to learn on your coach so YOU keep at this and don't get over flustered. Walk away, take a break, and go back at this looking at it from a different angle.

Mike

Re: AC Breakers

Reply #14 – April 19, 2022, 08:32:18 am

Mike,

You might also test for 12VDC in the thermostat's phone plug. Try all combinations of the contacts though usually the red and black are for 12 volts.
The plastic dividers usually are in the way, so you no need paper clips or straight pins held against the meter probes to touch the phone plug contacts.

It also is quite possible that the off-on switch is corroded and/or too loose inside. This is what I repair or replace along with replacing the worn out push buttons.

Jim Frerichs
2002 U320 42'

3zero8four4zero51five4

Re: AC Breakers

Reply #15 – April 19, 2022, 12:09:38 pm

Mike/Jim/Turbojack
I found the #52 breaker at the front dash, disconnected the 2 wires attached, waited a few minutes and then re connected. No joy. I purchased 4 new 4 pin telephone couplers and installed them

The front phone cable from the thermostat is silver in Color coming out of the thermostat. There are two silver cables in the front AC which are joined together by a coupler. There are two black phone cables joined by a coupler at the front ac as well. I did notice one of the black cables has the the little "click" tab off of it but I pushed it in securely. The pic attached show the fron ac with all the cables attached. The right silver cable was detached which is how the unit fired up the front ac as stated before. I have sprayed all the connectors with contact cleaner. The second photo shows the rear ac with one silver cable coupled with a black cable. The second coupler has a black cable plugged into it by nothing connected to the other side
LOST for words here......
I guess I should ask...would an AC RV specialist be able to diagnose the issues quickly?? Any idea of costs. I am in Canada so the prices of course will differ.

Re: AC Breakers

Reply #16 – April 19, 2022, 12:11:29 pm

Additional pics of the rear ac and thermostat

Re: AC Breakers

Reply #17 – April 19, 2022, 02:03:46 pm

You are doing great!!!!

Very good chance you are going to pay someone to learn how the system works and how to trouble shoot the problem. I would say about 20% chance you will find someone that can do a better job then you are doing.

Now with that said.

Go up on the roof, Remove the covers and then remove the metal (I believe) cover to get access to the circuit boards. First check and make sure everything is plugged in tight. Look the circuit board over and verify that there are no burnt spots on the boards. (front and rear AC's While you are up there, take pictures like you have done. I am thinking the phone wires are plugged into the circuit boards. While you are looking at the board you may be able to see where the 12V DC is connected to them and verify that the rear board has 12 volts.

Re: AC Breakers

Reply #18 – April 19, 2022, 02:46:24 pm

Turbojack
Now that you mention it, I was up on the roof and looking at the rear ac with the cover off. The two black phone connectors are connected on the circuit board and I noticed one of the connectors was a little loose from the circuit. I did not think too much about it but maybe maybe that is the reason?? But does that explain the no power at the thermostat? Almost tempted to install the 5 button thermostat and both new circuit boards ( which was my intention anyway) to see if that remedies the issue. Laughed about what you said about the cost of having it done. Again, thanks for all the suggestions...like I said this is brand new scary territory for me!

Re: AC Breakers

Reply #19 – April 19, 2022, 03:10:11 pm

Peter,
I had a similar issue like you a couple of years ago. Had both A/C's on High Cold and plugged in to a 30 amp circuit ( I know, brain lapse). Everything was fine for a short while, then both A/C's quit working. I could unplug the 5 button T-Stat and reset and all would work again, for about a minute, then go dead. I assumed I fried the T-Stat, so replaced it. Worked for about 5 minutes, then all dead again.

I got on the roof and removed the covers and unplugged the circuit boards, then reset, same result, all good for about 5 minutes, then dead.
Got a new circuit board for the front A/C, hooked it all up................Been working great for 3 years now !

If I remember correctly, paid about $80 for the T-Stat and $110 for the circuit board. My plan was to replace parts one a time until it worked. For $200 and a little !@&%! language, I got it working. Figure I was still way ahead money wise than calling a service, plus I can be pretty stubborn sometimes.

Something else, if I believe that those circuits boards have some fuses on them. May be worth a look.

Re: AC Breakers

Reply #20 – April 19, 2022, 05:14:43 pm

Beginning to think I should start by changing to the 5 button thermostat and 2 new circuit boards and go from there

Re: AC Breakers

Reply #21 – April 19, 2022, 06:36:13 pm

Just a WAG but are you sure the couplers are okay? I've never seen this type of coupler.

Re: AC Breakers

Reply #22 – April 19, 2022, 07:02:00 pm

The coupler are standard phone couplers. There were the exact ones on there before the issues started

Re: AC Breakers

Reply #23 – April 19, 2022, 07:59:49 pm

The Dometic couplers are not the same as a phone connector. They look alike but internally are different. You will need to check the 3 amp fuse in the upper circuit board in both ac's. I have fixed these issues by using contact cleaner on the cable ends and also inside the couplers. The Dometic cables are data not phone cables so they are not interchangeable. You may have blown the 3 amp fuses in the upper circuit boards. Put everything back together as original and start from there. You might have to look up how to reboot the thermostat so that it will recognize all parts of the system. You should be able to find how to do that on the internet.

Re: AC Breakers

Reply #24 – April 21, 2022, 02:03:14 pm

Remind me please.. to work on the ac on the roof, disconnect the #52 connections for 12 v on the passenger side dash , disconnect shore power and switch ac breakers off at foot of bed??? Correct or am I missing something?

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