Coach thermostat won't show zones

[weston47]

I finally had a chance to monkey around with the testing of the wires. To be clear my thermostat doesn't indicate with the word zone or any number it is just blank. I used a test wire from the Tstat to the rear phone connection on the front AC unit. With the test wire connected the front unit works exactly the same as taken from the wall which would indicate to me the wire from the AC to the wall Tstat is fine. Next I connected the front phone wire to the back jack in front AS and disconnected it from the rear AC and plugged in the Tstat back there and it lit up but would not start the Front AC so my thinking is that the phone wire going back to the rear AC from the front AC must have something wrong or it would have started the unit like it did with the test wire. I am as far away from being an electrician as you can get but as of now I suspect the problem could be in the wire connecting the two units. I will try to get a wire that is 30' long and see if it makes a difference. While looking at the rear unit I noticed the six wires blue yellow red back and found they are about six inches long and not connected to anything. Don't think I have heat pump action on these units. Thanks again for all of the input I will keep trying and let you know how it turns out.

[Tomjhall]

I have a document that I used to fix my units. It's a few meg so I don't know if I can attach it but I'll try.

FYI, my background is longhaul fiber optics and telephony. I work for the FAA as a comm engineer. Duo therm uses this telephone cable as a data cable but they refer to it as a telephone cable.... go figure.

Check out pg 44 of the pdf file or pg 45 of the book it has the info on the cable. It's loaded with great info.

Well it's over 3M so i tried to upload it to the "files" section of this forum. It's not approved yet, so you can't see it. If you email me I will send it to you.

tomjhall@comcast.net

[Tomjhall]

I named it Duo Therm CCC. There are a few other documents on there but the one I uploaded has info for the 4 button stat.

The cable is 4 wires, and uses RJ11 connectors which you can find at radio shack. You make the cable straight thru.

5.2 CABLE ASSEMBLY
A flat telephone extension cable must be routed from the
unit to the Comfort Control Center. It must be 26 gauge,
stranded copper wire, four (4) conductor (yellow, green,
red and black). The cable must be terminated with a four
(4) position telephone RJ-11 connector.
NOTE: DO NOT USE A PRE-MADE TELEPHONE
EXTENSION CABLE. THE POLARITY OF THE CONNECTORS
IS REVERSED AND WILL CAUSE A
FAILURE OF THE SYSTEM.
The cable assembly should be made in the following
manner:
Cut the modular cable to the desired length. When cutting,
make sure ends are cut straight, not diagonally. Next, use
an RJ11 connector crimping tool.
Use the stripper section of the tool's blade to remove the
outer insulation from each end of the cable. Be careful not
to remove or break the colored insulation on the inner
conductors.
NOTE: Fully insert the cable into the stripper slot,
holding cable in one hand and tool in the other hand.
Squeeze down on tool and pull away. This will remove
the correct amount of outer insulation for insertion into
RJ-11 modular plug.
Now you are ready to insert the prepared cable into the
RJ-11 modular plug. When inserting cable into plug, you
MUST be sure that the black wire is on your left as you
look at the top of the plug (with the spring clip facing you)
and that the conductors are flush with the tip of the plug
and touching the small teeth-like gold conductors. Insert
the RJ-11 modular plug with the cable into the tool's
cavity, squeeze down to the STOP and hold for a few
seconds. This completes connections for one end of the
cable. To prepare the other end of the cable, repeat this
procedure.

good luck

[Tomjhall]

I attached a picture

[weston47]

Again thanks to all who have given their time to help me figure out my thermostat and zone issue. Good news I have it fixed. Got a 30' phone cable and cut one end off and twisted the wires so they were the same on both ends and hooked up the Tstat to the wire and was able to get the front unit working so then took the cable and plugged it in to the rear unit and low and behold the zones 1 and 2 started showing and could get both units to work like the should. Next issue was to get the wire that was dangling from front to back up in the ceiling. Thought I could just pull it through with the bad wire but no way. While pulling on the wire I found where a rodent had chewed the black wire in half and this was my problem all along. Was able to get just enough to cut and twist together then some liquid tape and a gob of silicone and put it back together and it works.

Now I noticed some dead rodent smell up there so a new problem to deal with.