How can I diagnose my Motorhome Slideout electrical problem?

My 94 Newmar Motorhome Slideout stopped working and I replaced the slide controller but that wasn't the problem. When the switch is pressed it sounds like the controller is trying to make contact and the LED lights sometimes but goes right off. I tried jumping the switch with no luck! I pulled the battery and ground wire off the controller and did a volatage measurement which tested at 13.50V. I tried jumping the controller switch and grount terminals and got the same contact sound so I am assuming the switch and wire is OK. The only wires not tested are the 2 Red motor wires which could have been damaged by a rodent or perhaps the motor died. Can I apply 12 Volts with my battery booster directly to the motor see if its OK and if so how would I hook it to the two wires entering the motor. Would one be a ground wire? The colors are red/black on one and the other is lime green. Should I disconnect the battery connections on the relay 1st or perhaps the battery itself? Is this the correct way to proceed?

You can apply the booster to the motor but make sure you have the polarity right and be ready to abort it quickly. I suspect the system has an interrupt when it detects a short which is why the LED goes off immediately.

A good visual inspection of the wires to the motor should give you a clue as to whether it's the wires to the motor or the motor itself.