You might be able to find a replacement motor alone, from China, if you search on Amazon, Ebay, etc. You take a bit of a risk on the quality, but sometimes it works out OK. Try to make sure that the seller explicitly verifies the compatibility with your year and model.
Have you verified that the fault lies in the motor itself? Make sure that your battery is fully charged. It should measure 12.7 volts across the battery terminals. 12.0 Volts is a half discharged battery and 11.5 Volts is essentially a dead battery. Low voltage to the motor can fool you in your diagnosis.
It might pay to jump that 12.7 Volts directly to the motor positive wire (Red/White stripe wire) from the battery positive terminals. That will bypass all of the other stuff in the circuit.
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