To quote the 700/900 FAQ's

"Wipers Are Slowing Down.
[Inquiry:] I noticed my wipers to be sweeping slower than usual lately, and a whirring sound to be coming from the wiper motor. There was even an instant that the wipers would not sweep, before it suddenly came to life and began to sweep slowly. Fuse was OK. Windshield was very wet with rain. Wiper rubber strips are 3 months old. Is my wiper motor about to die? Or should I squirt some WD-40 somewhere to loosen up the motor?
[Response: Richard Klasic] It's hard to describe but the wipers are mounted on the shaft going through a bushing. After years of usage. this bushing becomes dry and corroded making the wipers move more slowly until they freeze completely. You need to take out the shafts and polish them gently with sandpaper and then lube the shaft with a grease that doesn't go away with water. You can always unhook the motor from the ball joint to the wipers and see if it runs fine. I bet it does. This was the case on my wipers on the old 760 I had. It really squeeked when running. And after 15 minutes hammering at the tap with a plastic hammer and lot of WD-40 it finally came loose. After my operation WOW the wipers were dead silent and swept like lightning over the windshield."


So, my question is: Do i have to go under the dash to do any of this? I'm sure I pretty much want to clean the ground on my motor, and try this technique, but i'm not sure if it's a bear of a job to do, or not. I really don't want to take off the dash to do this... Although, i DO have to still attempt the blower motor...
--
'89 245 DL B230 Manual