I am trying to diagnose why my 2001 Honda civic lx rear driver side electric window does not work. Here is what I discovered so far:

rear switch up: motor works/spins
rear switch down: motor does not work/spin
front master switch up: motor does not work/spin
front master switch down: motor does not work/spin

Voltages measured at the motor:

Voltages measured at the motor:
rear switch up: -12.0
rear switch down: - 0.1
rear switch neutral: - 1.3
front master switch up: - 1.3
front master switch down: + 1.2
front master switch neutral: - 1.3

With 12v applied to motor it works/spins
With reversed 12v applied to motor it works/spins opposite direction.
So it appears the motor is OK.

So what could the failing component be:
1. rear switch?
2. front master switch?
3. Is there a relay it could be?
4. something else?

Thanks....