Upgrade to Digital Thermostat

[KHabie]

I have a 2017 Jayco 31P. I was unhappy with large temperature swing with the analog thermostat Part # RVP No. 7330F3858. I was told to purchase 8330-3862 which is suppose to be a wire for wire replacement. The wiring behind the thermostat is a joke.....many splices and color changes. However, I change out the thermostat one wire at a time and wired it by color to match old thermostat. The heater works properly, however I only get the fan on Cool. I get two speeds but no compressor. What did I do wrong? The white wire on the new thermostat came with a wire nut on the white wire, not sure what that meant, all other wires were stripped. Any help would be appreciated.

[JimD]

I installed that exact thermostat in my 2017 Greyhawk with no problems. The way this thing works is that it simply sends 12 volts to each item to energize it. 12 volts to the furnace, 12 volts to the fan, and 12 volts to the compressor.

Best guess is that the 12 volts is not being routed to the compressor for some reason. The first thing to check is that the 12 volts is coming out from the thermostat on the compressor line. Simple voltmeter check.

If it is coming out correctly then maybe there was a wiring error during install or maybe one of the wonderful Jayco splices is bad. You can't rely on Jayco using the correct wire colors. When I swapped mine I ignored the wire colors and instead swapped over to connections that had the same identification.

You could jumper the 12 volts to various wires, as long as it isn't a ground connection, and see what turns on.

[KHabie]

Thank you for the reply. As I see it the yellow wire should have 12 volts on it when I switch to Cool. I will get a meter out and check that. I wired the yellow wire on the new thermostat to the same wire coming through the wall that the old thermostat yellow wire was wired to .

[KHabie]

Thank you Jim for your advice. I have been involved with my grandsons the last couple days and had to leave the thermostat project. Ya gotta spend time with the grandkids while they still think you are good guy....😊
I got back to the MH and tugged on a few splices, my plan was to put a meter on them once I confirmed they were tight. Did not have to........the second one I tugged on......the wire came right out....😡 I correctly spliced the old splice, checked the rest and Shazam.......it all worked as intended.
Thanks again for the help. 👍

[Jwhite3733]

Purchased honeywell rth2300 to replace analog thermostat. Problem is son pulled all wires loose without labeling or pictures.
I will show pictures of what I have and what I know. I believe 1st pic is from ceiling unit. Here is where I know the small red wire goes to yellow wire on old and yellow slot on new honeywell.
The 2nd pic which is board. No idea what went where except yellow wire to small red wire in wall. The 3rd pic is new digital. I tried as pic shows, then tried how a YouTube said.
I had small red wire from wall to yellow on digital unit. I had green to green. I had large red wire to the R ( with jumper still in R_RC) the blue wire twisted w large white in wall..not connected to digital. The small white also not connected to digital....nothing works, no fan, no ac, no heat.
Tried same above but small white wire to white, small blue wire to blue, large white not connected..again nothing.

I'm lost.

How can I even test separately each component..fan? Ac? Heat? Just by touching wires?

[JimD]

Originally Posted by Jwhite3733

Purchased honeywell rth2300 to replace analog thermostat. Problem is son pulled all wires loose without labeling or pictures.
I will show pictures of what I have and what I know. I believe 1st pic is from ceiling unit. Here is where I know the small red wire goes to yellow wire on old and yellow slot on new honeywell.
The 2nd pic which is board. No idea what went where except yellow wire to small red wire in wall. The 3rd pic is new digital. I tried as pic shows, then tried how a YouTube said.
I had small red wire from wall to yellow on digital unit. I had green to green. I had large red wire to the R ( with jumper still in R_RC) the blue wire twisted w large white in wall..not connected to digital. The small white also not connected to digital....nothing works, no fan, no ac, no heat.
Tried same above but small white wire to white, small blue wire to blue, large white not connected..again nothing.

I'm lost.

How can I even test separately each component..fan? Ac? Heat? Just by touching wires?

First you must determine which wires are your +12 volts and ground. Do this with a voltmeter. After that you can simply touch the 12 volt positive wire to each individual wire and see what activates. One will fire up the furnace, one will turn on the AC fan, and one will turn on the AC compressor.

Once you know what each wire controls you can connect them to the new thermostat by function. The thermostat should have documentation stating what each terminal is used for.

[KHabie]

Jim is absolutely correct. With your meter on the ohms scale, find the wire that rings to ground. One meter lead on a good ground and touch the other wires one at a time until to get a reading, that will be -12 wire. Put the meter on DC Voltage and touch any of the other wires looking for a reading of around 12 Volts DC, that will be your +12 wire. Now take that +12 Volt wire and touch the remaking wires one by one. You will turn on the fan with one wire, the heater with another wire and the AC with another. Put the identified wires to the appropriate wires coming from the new thermostat. The wiring diagram from the new thermostat should identify the wires. Hope this helps, let us know.

[KHabie]

I wish people would post again when the figure something out, just to let everyone know that his problem is solved. 😡

[wisco]

Anyone install a Wifi thermostat? I have an ecobee stat I won and wondering if I could get that working in the '21 Precept 34G.

[KHabie]

Nope. While traveling I would not want to depend on WiFi or Blue Tooth, not dependable enough.