2 things, rear window motor, roof lights
 

my rear window in my 2006 f-350 lariat got stuck when opening the other day and so I opened the back fabric up behind the seat and my cables are in tact, but I hear a crunch sound in my motor and it looks as though the cable is bunched up in the motor. Should I just replace the motor and the cable section? if so, where is the cheapest place to by a replacement, what is the part number, and does the window have to come out to do so?

secondly, one or two of my roof lights will occasionally not come on and when I tap the top of the truck with my hand, it comes back on. How can I fix this? My speedometer is doing the same thing on about half of the gauge. This occasionally happens to the lights on the back of the cab (brake and normal lights). Is it a lack of ground or is it just a corroded connection? What is the best fix?