[Laird Scooby]

What Luke said Russ! ^^^^^ It might show you have 12V coming out of the switch under no-load conditions but as soon as the motor is connected, that will drop considerably. It's almost always the switches that fail in the way Luke described, rare that the motors fail. I think i have a spare motor but would need to check.

Talking of the motor, you may find that it runs backwards and forwards on the switch if you unbolt it from the roof assembly. This again demonstrates the switch can only pass a certain amount of current. You will also notice that it automatically stops in the closed position when you send it in either direction from a fully open position - bear this in mind when refitting it as getting it one tooth out can result in the panel sitting proud or recessed in the roof.

If you don't fancy pulling the switch apart, with the ignition off, spray some switch/contact cleaner in the gap between the switch rocker and housing then "exercise" the switch in both directions several times. Repeat a couple of time, finishing with a good squirt just into the gap and leaving it for 20 minutes or so for the alcohol to evaporate before testing with the ignition on.

You have already proved the motor works though and the only microswitches are built in to the motor assembly.