So I just moved into this house and it got warm enough to run the A/C only When i set the T-stat to cool only the indoor fan comes on. The outside unit does not. The outdoor unit is a older lennox while the furnace is a 2019 Tempstar model N8MSN0701412A SERIAL A191914814. I don't know if something got screwed up in the wiring when the new furnace was installed. The outdoor unit runs if I push the contactor in and a voltage meter shows it's not getting 24volts. At the control board on the indoor unit there is a 24 volt transformer that is sending 24 volts into the control board. Where it goes from there I don't know. I have 3 wires at the T stat as shown in the pictures. I only have 3 wires in the wall. I have multiple wires on the board terminal. Which ones send power to the contractor if any?

Thermostat wiring with R and RC jumped(not by me)


Info off the furnace


wiring at the main board inside the furnace


The main board itself


This crazy setup from the power company. I don't know if this has anything to do with it


A brown cable goes from the board and is tied into this

 

Unwrap the tape and see what is underneath. Cheap/dirty solution might be to put a jumper wire between G and Y on the furnace control board. Otherwise you need to trace wires end to end to figure out what is going to what.

 

It looks like at thermostat.....
R - red
W - white
Y - black

It looks like a blue on Y on the furnace board.

That box on the outside wall looks like an energy management controller from the POCO. You cannot bypass it if it's on your POCO bill.

 

Ok did some more investigation. There are no status lights lite on the green box that has a wire going to the A/C. I turned the T-stat to cool the indoor blower came on I went outside and no indicator lights on the box. This is where it gets interesting.I looked at the wiring on the board. I got a brown wire coming out of the furnace that is wired nutted that you see in the picture in post 1. It has a Red wire on C and white on Y.

They are not connected to anything. They were left connected on the board but are just wrapped around the duct. I have a 4 wire that goes up into the ceiling. It is wired as follows on the board, Blue on Y red on R White on W and green on G. Where it goes into the ceiling I don't know. I'm assuming the T-stat. Now This is really strange. I found some wires in a conduit coming up from the floor that do not go to anything. I'm betting that these go to the wires that I found disconnected. I've got pictures.

Info on the outdoor unit