Elusive wiper problem
 

I've been having problems with my wipers for a while now and can't seem to find the source. The reoccuring broblem is they simply wont work in either the slow or fast settings. This is accomanied by a buzzing sound when in the slow setting, but not in the fast setting. This indicates that the fuse has blown. Replacing the fuse works for a little while, but it always blows again. My freind who is a mechanic thought it was a problem in the multifunction assembly so I replaced that with no change in the symptoms. I my dad, who is an electrical engineer, did some fiddling with a volt meter and said the wiper motor was receiving all the right signals so his best guess was the motor was bad. I've heard this is uncommon, but I replaced it anyway (and also replaced the blown fuse). This fixed the problem for a while but eventually the same symptoms happened again. Everyone is telling me there has to be a bad ground somewhere. The ground on the wiper motor itself is easy to locate, but are there any other grounds I need to check/clean up?

Have you taken the wiper linkage off and made sure there is no binding parts and/or lubricated the linkages?

Thanks for the suggestion. I haven't specifically inspected the linkage but I had to disconect it to replace the motor and it moves very smooth. Also, replacing the fuse gets it to work for a little while so its an electrical issue.