Need thermostat wiring help

[Darrel]

First I must describe my problem.... In my 2007 KSDP 3912, the Duo-Therm comfort control center began to malfunction. It would start the furnace and after about a minute go dormant (display go blank) and the furnace would shut down. This would repeat in about 10 minutes with the result that no appreciable heat was generated. Switching off/on did not improve the situation. Trying heat pump setting did no good because the controller would go dormant before the 2 minute wait built into the heat pumps had expired.

Step 1) Wiggling wire and reconnecting/cleaning 4 lead phone type connector did not help.
Step 2) New controller purchased. When installed displays "EE". Called Dometic help line and went through set-up steps with no help. Support person said it is a "failure to communicate" problem and the controlled units are not responding.
Step 3) Furnace has no visable connectors at all. (Removing furnace would be ugly job!)
Step 4) Each AC had a pair of 2 wire connectors and bank of dip switches for programming. Wiggled wires and toggled dip switches. No help.
Step 4) Reversed settings on both AC units. No help.
Step 5) Wiring investigation - - 4 lead phone type lead at controller was somewhat pinched behind bracket. Removed bracket and enlarged wiring slot. No help.
Step 6) 4 lead wire from controller disappears upwards in chamber housing black water tank vent. At Each AC unit a pair of 2 lead connectors arrive. Somewhere between controller and ACs/furnace there is a splitter of some kind. Where on earth is it and how to access?????

Sorry for the long post. If anyone can supply any helpful insights or information it would be greatly appreciated.
Have a nice day - Darrel

[Luv2go]

Darrel:

Here is a troubleshooting manual for the 5-button thermostats:

http://www.nwrvsupply.com/manuals/du...leshooting.pdf

According to this, the thermostat's 4-wire cable should go to the first A/C, then the first A/C's second cable should go to the second A/C. I don't know what the second cable on the second A/C does. The furnace is hooked to the front unit. Note this is the example in the manual, if your Zone 1 was the living area and zone 2 was the BR, and furnace came on in Zone 1 then your coach should be hooked up this way.

If your coach has a 3rd zone then from the second A/C should go to the third A/C. If the 3 A/C's have two phone cables then I still don't know where it goes (of course there are coaches with 4 zones)

The manual shows you how to tell which unit is which zone and which should have a furnace by looking at the DIP switches (p5).

Also, according to the manual, the furnace is connected "to the two (2) blue wires from the control box" and does not use a phone plug. Perhaps one fell off or is broken?

It sure sounds like the cable from the thermostat is bad. Maybe try disconnecting the other A/C's connectors other than zone 1 and see if the it works?

Note the manual says they are not regular phone cables, the connectors are installed so pin 1 is pin 1 on the opposite end (with phone cables, pin 1 is pin 4 on the opposite end). If you can make or modify a phone cable (involves cutting one end or a cable and crimping another RJ11 jack on the cable) you can substitute a known-good cable between the thermostat and zone 1 A/C. You may be able to get crimpers and RJ11 jacks at Radio Shack, maybe even at Home Depot or similar store. There's a picture (Fig 2 on p4) that shows you how how the cable should look when you're done.

No problems with the long post, sorry for the even longer reply.

Stewart

[Route 66]

According to this, the thermostat's 4-wire cable should go to the first A/C, then the first A/C's second cable should go to the second A/C. I don't know what the second cable on the second A/C does. The furnace is hooked to the front unit. Note this is the example in the manual, if your Zone 1 was the living area and zone 2 was the BR, and furnace came on in Zone 1 then your coach should be hooked up this way.

After spending some time at the factory and talking to Norbert, Newmar's lead tech on this stuff and fridges, this is correct.

The second cable on the rear AC goes to the temperature sensor in the bedroom.

12 volts is supplied to the front AC control module which powers both AC's control modules and the CCC.

Somewhere between controller and ACs/furnace there is a splitter of some kind. Where on earth is it and how to access?????

I don't believe there is a splitter. What led you to a splitter?

[Darrel]

You guys are SUPER Obviously I was confused about how the leads were routed to the AC units and furnace. I downloaded the troubleshooting guide and it was just what I needed The day I found the IRV forum was one of the better days I have had.

Have a nice day - Darrel