Black wires to both air handlers


Old 02-10-19, 09:26 AM
Thread Starter
Join Date: Jun 2016
Posts: 1
Black wires to both air handlers

I have 2 air handlers, a Goodman for the downstairs and a Lenoxx for the upstairs. There is PVC running across the attic floor with 2 black thermostat wires running between the 2 units. Can anyone guess why this would be? I have to go up there tonight and I can see what they are attached to, I don't remember off the top of my head. I think it was from the "R" of the upstairs over to the downstairs unit and vice versa. It doesn't make much sense to me, by I am no electrical genius.

I am replacing my RAM 3MC4 board with a 19W94 later this week so I would like to get a full grasp on the wiring before I tackle it.

I am having an issue with the Nest E "no power to the "R" wire" thing. It happened a couple weeks ago and I went up to check all the wires. I think it was a short somewhere because I got it working somehow. I am going to look at it tonight, so I may have more questions coming. 😁
Sponsored Links
Old 02-10-19, 05:30 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 50,954
Likes Received: 154
Welcome to the forums.

With the 19W94 make sure you get the connectors/adapters needed for your furnace.
I'd need some pictures of where the wires connected. There shouldn't be any common connection between air handlers and furnaces. They run on different transformers.


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes