Toyota Repair: Toyota Avalon 1997 Wiper Motor, toyota avalon, motor toyota

Question
Toyota Avalon 1997 Wipers don't work.  Fuse is OK.  Turning on the wipers and one can hear to motor wining and sometimes the wipers spasms but never come up.

Any ideas on what's wrong and what to replace?
How to replaces?

Thanks

Answer
Here is what I think the problem is and it's real easy to fix.
Turn the wipers on and then off again, now remove the two plastic covers at the bottom of the wiper arms,make sure the wipers are at the bottom(rest) position, there is a nut on each wiper arm, tighten both these nuts and let me know if this solves the problem.