Ac unit runs, inside blower shuts off after 2 mins, compressor continues to run, t-stat still calling for cool

thru trial and error we determined our problem. I will tell here for others use what we did and the outcome.
Furnace problem when using AC

Ac was turned on....compressor outside and blower inside came on as normal....2-3 mins late, with thermostat still calling for cooling, inside blower shut off. We imme. shut off AC to protect from freezeup.

We figured: 1st that motor had over heated tripping the thermal protection. We turned on heat and it ran like normal til heat satisfied. OK, no thermal tripped.

2nd we thought perhaps a relay had gone bad or the high speed of the 3 speed motor had gone bad.

We looked at the electrical schematic for the old board and found the wiring for the (cool black wire) high speed, the (heat red wire) low speed, and two more plugs, one holding a blue wire that said (med speed) and one with no wire.

There was an addendum on the blue wire that said you could use a yellow wire for med high and an orange wire for med lo. There were no wires this color on the old board

old board was 1 hi cool black wire
2 lo speed heat red wire
3 med hi blue wire
4 med lo no wire

new board was 1 black we assumed high speed for cool as color matched old board
2 yellow we assumed med hi speed, per addendum for blue wire old bd
3 red we assumed lo speed for heat as color matched old board
4 orange we assumed med lo speed, per addendum for blue wire old bd

Now we have the missing colored wires from the old board to use.

So we thought each wire might have it own relay and if the high speed cooling relay was tripping, the other wires relays should be fine.

So we then unplugged the high speed black wire going to the motor from the board and plugged the red wire (lo speed) for heat to the circuit board in place of the black (hi speed) wire.

We then turned power back on to AC and furnace. Set the thermostat to call for AC and everything came on and worked fine all the way thru to thermostat shutting it down when temperature satisfied.

We found that lo speed red wire was too low a speed to give much flow to the heavy cooled air, so we put the red wire for lo speed heat back where it belonged.

We then took the yellow wire assumed to be med-hi speed, per the old boards addendum, and connected it to the high speed cool (black) plug on the circuit board and redid our test of the functioning of the AC.

The AC and blower came on together and ran til thermostat shut everything down on temperature satisfaction.

Our AC is working......and we deduce that the problem is not a relay, because the relay did not trip and shut the blower down prematurely after the wire change told the blower motor to use a different speed than high.

We have decided that its a blower motor failure in the high speed circuitry of its 3 speed motor, as the other speeds work with no blower shutdowns. Need to replace motor or let it run at medium speed. Which to be determined.
hope this helps someone else in diagnosing a problem thru trial and error we determined our problem. I will tell here for others use what we did and the outcome. Furnace problem when using AC Ac was turned on....compressor outside and blower inside came on as normal....2-3 mins late, with thermostat still calling for cooling, inside blower shut off. We imme. shut off AC to protect from freezeup. We figured: 1st that motor had over heated tripping the thermal protection. We turned on heat and it ran like normal til heat satisfied. OK, no thermal tripped. 2nd we thought perhaps a relay had gone bad or the high speed of the 3 speed motor had gone bad. We looked at the electrical schematic for the old board and found the wiring for the (cool black wire) high speed, the (heat red wire) low speed, and two more plugs, one holding a blue wire that said (med speed) and one with no wire. There was an addendum on the blue wire that said you could use a yellow wire for med high and an orange wire for med lo. There were no wires this color on the old board old board was 1 hi cool black wire 2 lo speed heat red wire 3 med hi blue wire 4 med lo no wire new board was 1 black we assumed high speed for cool as color matched old board 2 yellow we assumed med hi speed, per addendum for blue wire old bd 3 red we assumed lo speed for heat as color matched old board 4 orange we assumed med lo speed, per addendum for blue wire old bd Now we have the missing colored wires from the old board to use. So we thought each wire might have it own relay and if the high speed cooling relay was tripping, the other wires relays should be fine. So we then unplugged the high speed black wire going to the motor from the board and plugged the red wire (lo speed) for heat to the circuit board in place of the black (hi speed) wire. We then turned power back on to AC and furnace. Set the thermostat to call for AC and everything came on and worked fine all the way thru to thermostat shutting it down when temperature satisfied. We found that lo speed red wire was too low a speed to give much flow to the heavy cooled air, so we put the red wire for lo speed heat back where it belonged. We then took the yellow wire assumed to be med-hi speed, per the old boards addendum, and connected it to the high speed cool (black) plug on the circuit board and redid our test of the functioning of the AC. The AC and blower came on together and ran til thermostat shut everything down on temperature satisfaction. Our AC is working......and we deduce that the problem is not a relay, because the relay did not trip and shut the blower down prematurely after the wire change told the blower motor to use a different speed than high. We have decided that its a blower motor failure in the high speed circuitry of its 3 speed motor, as the other speeds work with no blower shutdowns. Need to replace motor or let it run at medium speed. Which to be determined. hope this helps someone else in diagnosing a problem

Furnace problem when using ACAc was turned on....compressor outside and blower insidecame on as normal....2-3 mins late, with thermostat still calling forcooling, inside blower shut off. We imme. shut off AC to protect fromfreezeup.We figured: 1st that motor had over heated tripping thethermal protection. We turned on heatand it ran like normal til heat satisfied. OK, no thermal tripped.2nd we thought perhaps a relay had gone bad or the highspeed of the 3 speed motor had gone bad.We looked at the electrical schematic for the old board andfound the wiring for the (cool black wire) high speed, the (heat red wire) lowspeed, and two more plugs, one holding a blue wire that said (med speed) andone with no wire. There was an addendum on the blue wire that said you coulduse a yellow wire for med high and an orange wire for med lo. There were no wires this color on the oldboardold board was 1 hi cool black wire 2 lo speed heat red wire 3 med hi blue wire 4 med lo no wirenew board was 1 black we assumed high speed for cool ascolor matched old board 2 yellow we assumed med hi speed,per addendum for blue wire old bd 3 red we assumed lo speed for heat as color matched old board 4 orange we assumed med lo speed,per addendum for blue wire old bdNow we have the missing colored wires from the old board touse.So we thought each wire might have it own relay and if thehigh speed cooling relay was tripping, the other wires relays should befine. So we then unplugged the high speed black wire going to themotor from the board and plugged the red wire (lo speed) for heat to thecircuit board in place of the black (hi speed) wire. We then turned power back on to AC and furnace. Set the thermostat to call for AC andeverything came on and worked fine all the way thru to thermostat shutting itdown when temperature satisfied.We found that lo speed red wire was too low a speed to givemuch flow to the heavy cooled air, so we put the red wire for lo speed heatback where it belonged.We then took the yellow wire assumed to be med-hi speed, perthe old boards addendum, and connected it to the high speed cool (black) plugon the circuit board and redid our test of the functioning of the AC. The AC and blower came on together and ran til thermostatshut everything down on temperature satisfaction.Our AC is working......and we deduce that the problem is nota relay, because the relay did not trip and shut the blower down prematurelyafter the wire change told the blower motor to use a different speed than high.We have decided that its ablower motor failure in the high speed circuitry of its 3 speed motor, as theother speeds work with no blower shutdowns. Need to replace motor or let it run at medium speed. Which to be determined. Furnace problem when using ACAc was turned on....compressor outside and blower insidecame on as normal....2-3 mins late, with thermostat still calling forcooling, inside blower shut off. We imme. shut off AC to protect fromfreezeup.We figured: 1st that motor had over heated tripping thethermal protection. We turned on heatand it ran like normal til heat satisfied. OK, no thermal tripped.2nd we thought perhaps a relay had gone bad or the highspeed of the 3 speed motor had gone bad.We looked at the electrical schematic for the old board andfound the wiring for the (cool black wire) high speed, the (heat red wire) lowspeed, and two more plugs, one holding a blue wire that said (med speed) andone with no wire. There was an addendum on the blue wire that said you coulduse a yellow wire for med high and an orange wire for med lo. There were no wires this color on the oldboardold board was 1 hi cool black wire 2 lo speed heat red wire 3 med hi blue wire 4 med lo no wirenew board was 1 black we assumed high speed for cool ascolor matched old board 2 yellow we assumed med hi speed,per addendum for blue wire old bd 3 red we assumed lo speed for heat as color matched old board 4 orange we assumed med lo speed,per addendum for blue wire old bdNow we have the missing colored wires from the old board touse.So we thought each wire might have it own relay and if thehigh speed cooling relay was tripping, the other wires relays should befine. So we then unplugged the high speed black wire going to themotor from the board and plugged the red wire (lo speed) for heat to thecircuit board in place of the black (hi speed) wire. We then turned power back on to AC and furnace. Set the thermostat to call for AC andeverything came on and worked fine all the way thru to thermostat shutting itdown when temperature satisfied.We found that lo speed red wire was too low a speed to givemuch flow to the heavy cooled air, so we put the red wire for lo speed heatback where it belonged.We then took the yellow wire assumed to be med-hi speed, perthe old boards addendum, and connected it to the high speed cool (black) plugon the circuit board and redid our test of the functioning of the AC. The AC and blower came on together and ran til thermostatshut everything down on temperature satisfaction.Our AC is working......and we deduce that the problem is nota relay, because the relay did not trip and shut the blower down prematurelyafter the wire change told the blower motor to use a different speed than high.We have decided that its ablower motor failure in the high speed circuitry of its 3 speed motor, as theother speeds work with no blower shutdowns. Need to replace motor or let it run at medium speed. Which to be determined.