I have a Trane XE60 that looks like it was installed in late 1989. I've owned the house for about 6-7 years now with no real issues to speak of, outside of a thermocoupler replacement. But about a week ago a metallic scraping/grinding sound started coming from the furnace blower. Eventually it would stop and operate normally. The frequency of the problem increased until now there is no air flow and all I hear is a low electric humming sound when I try to turn the air on.
I removed the furnace cover and tried to diagnose the problem myself (unsuccessfully). I did reach around and inside the shroud to see if the blower cage was wedge or scraping but it seems to move freely with no sounds. My guess is the motor itself is bad? or a bearing? Other internet research has pointed me to the capacitor that is mounted on the outside of the fan shroud - but would the symptoms I described result from a bad capacitor?
Any recommendations would be greatly appreciated. And given a cost estimate to fix/replace, would I be better off just getting an HVAC warranty, waiting 30 days and then just having them come take care of it?
Thanks in advance!