When I first bought my XJ, my rear wiper was completely dead so I replaced the whole assembly.........motor, arm, blade, gasket and collar.
It worked great...............for a while.

Now, it's going much slower than it should and it no longer "parks" (returns to it's original position at the bottom of the glass). As soon as I turn the switch off, it stops wherever it is when I do.

Time for a new motor?

 

Anyone???

 

Possibly a new motor how long has it been in? Is it used for mostly rain or scraping mud off the back glass? Lol you might try wiring direct to it see if it works properly like that I suppose you could have a draw in the loop or a bad connection but usually that would cause an intermittent problem rather than being slow

 

Check fuse for good connection had same issue on my 89.