Problem Solved!
I finally had enough of this... jsavage was right on this:

I removed the intermittent wiper relais (it is a pain to get it off, mounting screw is hidden, tough access 8mm nut) and pried the relais apart, to my disappointment there was no dirt or anything visually damaged inside, I moved the contact a little and gave it a puff of contact spray, reconnected everything and wow(!!!!!): everything works! Intermittent wipers run and park, stalk switch runs all three speeds and parks!

Bottom line: all the no parking problems can sometimes be the intermittent relays, cleaning contacts here worked for me. (BTW I have a used wiper stalk switch for sale now, LOL)

jsavage was right!
I pulled my intermittent wiper relais, pried the the case apart and gave it a puff of contact cleaner...
Everything works, wipers park with stalk switch, intermittent wipers work. I am ready for rain!!!
http://forums.pelicanparts.com/uploa...1362158182.jpg
wiper relais is behind the fresh air blower, it is mounted with an 8mm nut below the cable harness to the left of it (a major pain to get off)
http://forums.pelicanparts.com/uploa...1362158207.jpgIf you are more careful you can pull the relais apart without breaking the housing...plastic is pretty brittle though. There was no visible dirt inside, I just gave it a puff of contact cleaner and cleaned the plug connectors and now everything works....
It is not always the wiper switch contacts that cause you to loose parking, relais was definitely my cause!

Just replaced my Intermittent wiper relay located behind the fresh air blower. Fixed the problem wipers were erratic on intermittent, didn't park sometimes, and when I used the windshield washers they would wipe only once instead of three times.

sometimes the wiper contacts in the stalk get misaligned, if you can push on the wiper switch forward and everything works fine (wipers park, intermittent wipers work) than a little bending of the contacts is in order. John Walker has a good article on how to do this

I tried the stalk alignment twice and finally replaced the stalk switch, but it did not fix my problem. Cleaning the intermittent relay was the way to fix my park problem.

Just performed the relay clean, my wipers now park thanks to this thread! I also reversed the wipers while I was in there. Now I just need to replace the wiper stalk on the steering column, it only responds to the washer fluid function.

Reviving this not too old thread. Just finished repairing the major issue with my wipers (not working at all), now I am chasing the 'will not park' gremlin. The instructions were very helpful from Dkennel, especially the fresh air inlet hiding the two bolts of the blower. Wiring diagrams helped put it all back together at 2:00 this morning. Now with proper lube she works great.
Thanks Pelicans for saving my pocketbook yet again!
Cheers,

My fix for 911 wiper park issue
 

Thanks to my posts on pelican I was able to solve some electric issues on my car so to be fair I wanted to share my fix to a couple of wiper related issues and intermitted function.

Reconnect battery
1) I replaced the wiper switch iteself as it had to much play.. After a speedbump it would start wiping.. Problem solved with new switch
2) I checked the relais by turning the intermitted switch ( remove the clock and you can hear it mich better!). If clicking.. Stop buying a relais to test as it's likely to work. Nevertheless, i opened it ( first remove the blower etc..) and cleaned the contacts with some 400 grit sandpaper)
3) so switch, relay and intermitted excluded by the cause of my wipers not parking correctly.. Had to switch it off manually and in intermitted mode it would park in the middle.
4) now the wiper engine is the next one to look at.. Pain to remove with big hands.. And note down where the wires go! ( i tend to make a picture before removing anything). There are three bolts on the frame you can access via hood, 1 central nut that connects to wiper mechanism and two screws you get to by removing clock and speedo... How easy ;-)
5) I first looked at electric wires and the blue is the one that relates to park position! So... Connection wasn't great so I did reconnect again freshly
6) I opened the gearbox to see if any grease is stuck, looked ok, but cleaned it and put fresh grease in the... I cleaned the metal carefully and Slightly bent the three metal connectors and clean them with 400 sandpaper... Close it up, don't forget the gasket and then gradually tighten the screws crosswise
7) reverse..build in and connect the wires
8) reconnect the battery and in my case i heard the engine move a litte inside
9) solved!! Wipers, intermitted and park are fully operational... Main case of all this was a loose blue wire on the wiper enginehttp://forums.pelicanparts.com/uploa...1439474278.jpg
http://forums.pelicanparts.com/uploa...1439474314.jpg

Cleaning the relay contacts fixed my non-parking wipers.

wipers don't park
 

Pretty sure some of the parking problems are in the motor. When you turn off the wipers, there is a wire that is always hot that goes into the gearbox. Inside the gearbox you will find two or three contacts that sit on copper tracks on the gear. When you turn off the motor (or have it on intermittent) the contact sends 12V to a track on the wheel that carries the motor to the park position (no copper track as seen on the outside upper left of the gear in picture above, and red wire in same picture), then it stops.
When you turn the motor on, 12V comes in on another wire and contact to start the motor and move it off the park position.
So one of two things, the wire that is supposed to be hot all the time has no 12V, or the contact on the gear that carries the motor to park has lost its connection.
Bob B

I had a problem with my wipers just parking whenever I turned them off. They also wouldn’t stop wiping if I turned the knob.
Turns out, I had a bad wiper relay. My electrical engineering friend visually determined that it had a bad electrolytic capacitor. He replaced the capacitor and everything works again. (Relay is for a 1986 911.)