My AC is not working. It is a Trane AC (Model 2TTB0030A1000AA). In the process of diagnosis I tried replacing the capacitor, and that did not help. I tested the fan blades and they no longer spin easily. I purchased a new AC fan motor (the blades now spin effortlessly).
I have a problem trying to install it. There are 4 holes where the motor should mount to the top grill of the AC. The motor came with 4 fine-threaded bolts that presumably go into the holes. The bolts do not have thread cutting tips and those holes are not threaded! See attached photo.
Notice that the hole (where the sharpy mark is) is not threaded. The bolt in the image holds the housing together.
EDIT
Below I added is the corresponding hole in the old motor (notice the whole is threaded).
END EDIT
Question :
Did I get a defective fan motor, or am I expected to tap these holes?
Best Answer
Today I visited the parts store that I bought this from and they insisted that this was normal. He suggested that I use a power drill to drive the bolts into the case (no tapping of holes involved).
I followed his instructions and it attached easily and solidly. I suspect that the screws are a stronger metal than the holes in the case and the increased friction from displacing the softer case metal prevents the screws from loosening over time. This must be their solution in place of using loc-tite or lock washers.