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1.Do you have a meter for troubleshooting?
2. Give me complete model on furnace from label inside (Something like TUD08E
3.Tell me where you have fan wires connected on board
Let's do this. Turn thermostat to COOL. Take the meter and check between the Black COOL terminal and WHite NEUTRAL and verify we are sending 120v to motor. (Door switch will have to be held in of course)
Door switch IN?
OK does outdoor unit come on?
Check the little fuse on the furnace board and make sure it is not blown
Next check for 120v into transformer from XFMR terminals and then 24v out of transformer
Take your time
OK lets do this next. On furnace board, connect the R to G where thermostat wires hook up and see if blower comes on
You can leave wires connected. Use a jumper or a pair of needle nose pliers to touch R terminal to G terminal (Door switch IN)
OK if we have 120v into transformer, 24v out of transformer but no blower with R and G connected an no outdoor unit on call for cool with fuse intact you have a bad board.
You can connect the black fan wire to the XMFR to pick up power but it will run nonstop.
If you have further questions, please let me know.
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