I have never seen a working rear wiper.

I have a GXL and, of course, its busted.

Its NOT the switch......

Why do they fail like this?

I need as many people to respond as possible so that I can see what the top few resons are for the failure.

What say you?!

 

top reason-- the switch
But since U say it is not the switch; may I suggest checking the wires +/or connections on the hatch lift-arm (driver's side)... the top connection (closest to the rear wiper motor) has a tendency to drift up the arm, thus not giving a complete connection...
Other than that, U might want to check the motor itself to see if the grease or anything else is gumming up the works // also check the fuse, if the motor is gummed up or slowed for some reason, it could be causing the fuse to blow...
I have an 87 TII and an 88 GXL both with rear wipers, one works + one doesn't (mine is a switch problem combined with all the other things that I mentioned)
good luck!

 

The electrical connector on the hatch strut was broken on mine. I went to the junkyard and bought a good one for a couple bucks and now it works fine. You have to use the strut it's on though because it's not coming off without breaking something ( I had to refinish the strut a little as it had been in the weather for a while)