Help with Furnace/AC - Fan not working

Hello. I am having an issue with my central heat/air, and I could really use some assistance with troubleshooting it.

The issue I am having is with my inside unit, American Standard model# TWE031E13FB1. About 2 weeks ago I turned on the heat & the inside unit came on for about 5 seconds, but then it shut off for about 30 seconds, then it would start up again, then shut off again. It would cycle like this until I turned it off at the thermostat. The filter was a bit dirty, so I replaced it. Still no change. Inside the unit I could see the element heating up, but then it would make a clicking noise & it would shut off, this was the same time as the blower/fan was shutting off. In researching, it appeared that the high limit switch needed replaced. I pulled it, tested it and it was open, so I replaced it.

This seemed to solve part of the problem, it didn't make the audible click sound like it was before shutting down, but the blower/fan still wasn't running properly. When I turned the unit on and called for heat, the fan/blower would start spinning, but then after about 7 seconds it seemed to lose power for a moment and cut off for about 7 seconds, then it would start spinning again for another 7 seconds, then it would slow down for 7 seconds again. It will cycle like this until I cut the power or turned off the thermostat. I looked at the circuit board, but I did not see any melting, etc. One thing I did notice is that the CFM light on the circuit board went dark right before the fan cut off, then it would flash and light back up, over and over.

I removed the thermostat & placed a jumper wire between R and G, but I got nothing at all from the fan. I removed the jumper & replaced the thermostat, and there is now still no response from the fan. On the circuit board, both the FAN and CDM lights are lit, but no movement from the fan.

It does this same thing for both Heat and A/C, and it also does the same thing whether the thermostat is switched to ON or AUTO.

Where should I look next? What can I test myself? Someone please help.

Replace the blower motor capacitor. If you have the means, test it first otherwise it about a $10 gamble. If this does not fix the problem it could be the fan motor itself and will require further troubleshooting. Both/either of these conditions are responsible for the limit switch tripping. Good luck and please post back with outcome.

Thanks for the response. Would you by chance know where the capacitor may be located? I looked, but don't believe I see one. Here is a photo of my unit with the cover off.View attachment ImageUploadedByHome Repair1422831502.323318.jpg

I don't see it in the pic. Most likely mounted on the blower housing. You will have to pull the blower out to find it.

I don't believe there is a capacitor in this air handler. It's an ECM motor, which has a module on the back.

[ame]https://www.youtube.com/watch?v=5Q5mm1Nqx9U[/ame]

look on the door of the unit, it has a wiring diagram, it will show the capacitor...and what it is hooked to

you can find it from that

some units, have a led light that blinks when the unit is malfunctioning, count the blinks, then look in your owners manual for what # of blinks is what condition