Need help identifying c wire
#1
Member
Thread Starter
Need help identifying c wire
Hello! I am trying to install a smart thermostat but I am having some trouble identifying the C-wire in my unit. I have four wires at the thermostat and I need to attach the included c-wire adapter to go from four wires to five wires - (I'm sure it's common knowledge, but from R-G-Y-W to R-G-Y-W-C.)
I have a 12 year old Trane unit with no control board (at least not one that I have found). I have traced the wires the best that I could with my limited (non-existent) HVAC knowledge. I TRIED to read the wiring diagram...
I have attached pictures that I hope will help. Please let me know if more pictures are needed, or if you would like to see the diagram.
Thanks for taking a look!
Leslie




This last picture is just a full view of the wiring so you can trace the wires from their connection to the thermostat wires.

I have a 12 year old Trane unit with no control board (at least not one that I have found). I have traced the wires the best that I could with my limited (non-existent) HVAC knowledge. I TRIED to read the wiring diagram...
I have attached pictures that I hope will help. Please let me know if more pictures are needed, or if you would like to see the diagram.
Thanks for taking a look!
Leslie




This last picture is just a full view of the wiring so you can trace the wires from their connection to the thermostat wires.

#2
Welcome to the forums.
The cable that goes out to the condenser has a blue and yellow in use.
The yellow is the Y signal from the thermostat.
The blue wire is the C wire.
The cable that goes out to the condenser has a blue and yellow in use.
The yellow is the Y signal from the thermostat.
The blue wire is the C wire.
LPsquared
voted this post useful.
#3
Not exactly sure what converter you are using. I don't use them.
It looks like you have the wiring correct.
It looks like you have the wiring correct.
LPsquared
voted this post useful.
#4
Member
Thread Starter
Adapter connection
I thought as much! I just needed the confirmation! Thank you so much!
So, I will connect the smaller wires that I have labeled in the picture below to the 4 pins at one end of the adapter and then I will connect the corresponding labeled wires from the opposite end in their place, correct? (G with G, Y with the Y going to condenser, R with Blk, W with the 3 larger white)
Then the wire labeled C on the 5 wire end of the adapter will be attached with the smaller AND larger blue wires already held together with the wire nut (all 3 together)? I'm guessing the resistor stays connected right where it is?
Thanks again for your help!
Leslie

So, I will connect the smaller wires that I have labeled in the picture below to the 4 pins at one end of the adapter and then I will connect the corresponding labeled wires from the opposite end in their place, correct? (G with G, Y with the Y going to condenser, R with Blk, W with the 3 larger white)
Then the wire labeled C on the 5 wire end of the adapter will be attached with the smaller AND larger blue wires already held together with the wire nut (all 3 together)? I'm guessing the resistor stays connected right where it is?
Thanks again for your help!
Leslie

#5
That resistor was probably added to help a power stealing thermostat charge better.
You should be able to remove that now.
You should be able to remove that now.
#6
Member
Thread Starter
Thank you again for replying and for your advice about the resistor!
I'm sorry to continue to bother you, but could you please answer/confirm my other connection questions?
1.
and...
2.
Thank you!
Leslie
I'm sorry to continue to bother you, but could you please answer/confirm my other connection questions?
1.
I will connect the smaller wires that I have labeled in the picture below to the 4 pins at one end of the adapter and then I will connect the corresponding labeled wires from the opposite end in their place, correct? (G with G, Y with the Y going to condenser, R with Blk, W with the 3 larger white)
2.
Then the wire labeled C on the 5 wire end of the adapter will be attached with the smaller AND larger blue wires already held together with the wire nut (all 3 together)?
Leslie
#7
Member
Thread Starter
Thanks again!
You've helped me a great deal! (I will try to remember to post here if the connection was successful for the smart thermostat so others in the same situation can use this as a reference.)
Leslie
You've helped me a great deal! (I will try to remember to post here if the connection was successful for the smart thermostat so others in the same situation can use this as a reference.)
Leslie