Originally Posted by 
Michael2
				 
			D2 Auto Selector Switch. p/n UHB100190
Drill out the rivets
Cover Off
A cover showing water ingress damage
Lift the tabs over the wire crimps
Tab off - wire crimps revealed
Continue to remove the tabs
All the tabs off
I marked the position of the wheel - this is not necassary
Remove the wheel - notice O-Ring seal either side of it.
The wheel
The cams on the wheel that actuate the switch.
Clean with a contact cleaner that doesn't leave a residue
Prise out the whole assembly - do not remove the tan coloured tabs, and the micro-switches don't have prise open tops.
The silver contacts are moved by the cam on the wheel to actuate the micro-switches.  These cams have a mechanical function (not electrical).  They will wobble a bit, but test that when pushed firmly in, they have some spring resistance as the open the electrical contact.
The electrical contacts are on the outside of the assembly.  Clean these well, they're like indicator stalk switches in the nature of their construction.
Here you can see the wiring and both switches.
Remove the rubber seal and apply silicone to both faces, then reuse the seal and bolt it together using nylock nuts.