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moleary · 08-30-2013, 04:34 PM

Suddenly today my thermostat is no longer "seeing" zone 2. So my rear AC won't run. I've tried holding the mode and zone buttons down for a reset with no luck. Any advice?

**CLIFFTALL** · 08-30-2013, 04:37 PM

Fluorescent lights have been known to do this but the zone on mine said " 00 ". To reset mine I took the cover off the thermostat and removed the fuse for five seconds.

moleary · 08-30-2013, 04:41 PM

Mine is a 5 button. Pulled the thermostat off. No fuse.

**CLIFFTALL** · 08-30-2013, 04:43 PM

Then there must be a fuse somewhere.

moleary · 09-02-2013, 07:24 PM

Still struggling to trouble shoot my thermostat and/or rear AC.

Question: Do the data cables run from the thermostat to the front AC and from the front AC to the rear and nowhere else? In other words, do data cables run to the furnaces?

I identified the cable from the thermostat to the front AC. It seems to be good. I'm assuming the other cable plugged in to the front AC runs straight to the rear AC.

When I pull on this cable from either end it pulls out, like its broken in two. I don't want to pull too much until I'm sure it runs between the two AC's. If the cable is broke in two, how to I thread a new cable?

Dr4Film · 09-02-2013, 07:37 PM

How the data cables are wired can be in various configurations depending on the brand of coach and even the model so nothing is standard.

If you feel that the data cable from one A/C to the other A/C is the culprit, I would buy a length of flat phone cable that has four wires in it. Then crimp on new ends making sure that they are in the DATA cable format.

These are NOT phone cables.

Then hook up the new cable and see if the zone reappears.

The only way to run the new cable is through the A/C ceiling duct-work. You won't be able to fish it above the ceiling I believe.

Dr4Film ----- Richard

moleary · 09-02-2013, 07:48 PM

I've read that, while these cables have phone type connectors, they are different. How do I configure it as a data as opposed to phone? What's the difference? I would like to try this solution but I'm confused by the data vs phone configuration.

Luv2go · 09-02-2013, 07:48 PM

Quote:

Originally Posted by moleary

Still struggling to trouble shoot my thermostat and/or rear AC.

Question: Do the data cables run from the thermostat to the front AC and from the front AC to the rear and nowhere else? In other words, do data cables run to the furnaces?

I identified the cable from the thermostat to the front AC. It seems to be good. I'm assuming the other cable plugged in to the front AC runs straight to the rear AC.

When I pull on this cable from either end it pulls out, like its broken in two. I don't want to pull too much until I'm sure it runs between the two AC's. If the cable is broke in two, how to I thread a new cable?

Look here for troubleshooting/service docs for the Dometic 5 button t-stat systems. P7 of the "DuoTherm Comfort Control Center 5 button troubleshooting manual" shows where the data cables go, there also is some good troubleshooting info in it and the "DuoTherm Air Conditioner services manual". Most coaches with two A/C's follow this wiring scheme, it's a good bet that yours does as you've already confirmed the cable from the CCC to the front A/C.

BTW, the 5 button t-stat may have a polyfuse which is non-replacable (without a soldering iron). If the display lights up and controls zone 1 it is not the fuse. I vote for the data cable between the front and rear as you're suspecting. P3 of the CCC manual shows how to terminate the cables, as Dr4Film says it is not wired like a regular telephone cable, however you can get a telephone cable and rewire it so it will work. You can also splice the broken wires back together if you can reach where it's broken.

Hope this helps!

Luv2go · 09-02-2013, 07:59 PM

Quote:

Originally Posted by moleary

I've read that, while these cables have phone type connectors, they are different. How do I configure it as a data as opposed to phone? What's the difference? I would like to try this solution but I'm confused by the data vs phone configuration.

You posted as I was posting, see p3 of the CCC manual I linked to in the above posting. You can get a crimper, wire and connectors from your local home improvement store to make the cable, or if you have a phone cable sitting around and want to try it you can cut it, hold both connectors in the same orientation and splice the wires so the left pin goes to the left pin and so on.

moleary · 09-02-2013, 08:03 PM

I was just looking at the link you provided. I see the difference now. Think I'll run past Lowes tomorrow and pick up the stuff. Thanks for the info.

moleary · 09-03-2013, 09:28 PM

Update

I built a new data cable to string between the front and rear AC's. sure enough, that solved the problem. Pulled out the old cable and found it had been chewed completely in two about midway between the two units. Now I have to figure a way to route the new cable through the ceiling or duct work.

Damn mice are a pain in my butt. Wish I could find a sure fire way to get rid of them once and for all.

Thanks to everyone who weighed in with advice.