My furnace is overheating and I suspect that the blower motor does not go into high speed. Can anybody say what is the cause or how can I check if it indeed switches to high speed?
Here is the wiring diagram
and here are the specs. This sticker shows that it has a second speed. I suspect that switching to that second speed is not happening
the furnace is hotter in the areas marked on this picture. I suspect it might be either the blower at reduced speed or the heat exchanger that is cracked