[prairieschooner]

In the last 2 days I have had to RV techs say the motor has a thermo switch built in ans it is doing it's job because of the heat.
They say to replace it. Even if I found and replaced the thermo switch it probably wouldn't fix the problem as it is about the motor getting over heated. So what is causing the over heating. I may just have the motor rebuilt if I can't find another replacement.

This makes total sense to me and that is why I suggested bypassing the circuit board & testing it by itself.
Things just wear out...but if something has or is going wrong inside of the motor then....
The Thermo Switch can also wear out and by itself be an issue.
You may be able to save yourself some time & money but powering up the blower with an extension cord plugged into a separate circuit and you could prove/disprove the blower using a Volt Meter and Amp Meter.
As a side I found one of my A/C Units to have a bad Circuit Breaker a few years ago (they re roof mounted though). The problem was most likely because the connections were loose as Richard indicated previously, I tried tightening the terminals but the damage was already done.