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Are you saying the INDOOR fan does not run in AC mode?
OK since fan runs in heat mode, we know motor is probably ok. Issue is most likely going to be a bad relay (often built into the control board).In heat mode and fan mode different relays activate the fan than in cool mode. Do you have a volt meter so we can verify and do some troubleshooting?
Issue is not with thermostat if fan comes on in FAN On position and outdoor comes on in COOL position.
On call for cool the thermostat signals the indoor fan to come on and outdoor unit .If outdoor is coming on, the thermostat is sending the signal.
Lets just verify though. We can go to thermostat and touch the G and R teminals together with a wire or pair of needle nose pliers and see if blower will come on.
First step is to determine if we have a control board in the furnace or just fan relays.(I can tell that by model number).
2. If we have a board fan wires will be connected to terminals on the board marked HEAT COOL FAN and NEUTRAL.
3.On call for COOL we want to check between the NEUTRAL where fan wire connects and COOL terminal where fan connects. If we are not getting power out of board the relay for high speed is stuck open and board will have to be replaced.
4. If we do not have a board, basically same thing but instead of a board we will be checking power through the relay.
I am actually leaving in the morning to go camping but I can open this to other experts who will be able to pick up and work with you from here
Thanks Jim .I am going to opt now so another expert can help if I am gone wen you return.
Hello, I am picking this up from Airheatman. If you can take a photo of the fan motor wiring where it plugs into the printed circuit card, so that I can see the entire rest of the card, and where the thermostat wires connect....I can coach you as needed.
Use the paper clip icon at the right end of the tool bar for that, or the 'attach files' link to the left of your send button.
We can go from there.
Thats a good plan, see you later this morning.
Good work, glad you got it fixed.
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