Jeep Repair: Gr Cherokee - Electrical, rear window wiper, jeeps

Question
I have a 1997 Gr Cherokee, and occasionally I have problems where my rear window wiper moves extremely slow to the point where it stops.  Also one of my speakers pops off and on (sound cuts in and out) occasionally and the passenger rear door does not always lock when I use the auto-lock button on the driver's door.
Is there a common point that could be failing causing all of these problems to show up now and then?  It seems when one item is a problem the others are as well and when they work, they all work?
Any clues?

Dave


Answer
Dave,  sometimes when car parts are used offten they lose their strength and they evetualy just stop working.  But in your case the speakers are a main problem with jeeps because the wires tend to fall off in the door and you have to take off the door panel to fix it.