Welcome to AF sirpingalot !
I would bet you have some debrie in the switch thats causing this. Since it does work sometimes.
Best bet is to try wiggling it side to side rapidly, not to hard tho. ANd see if it doesnt clear the switch.
also try some compressed air(the can stuff works well) and see if it'll blow the debrie out.
Lastly pull the switch out and check the plug ins on the switch itself to see if they are corroded. Clean it up with a small file or snding paper is the connections are corroded.
I just posted some pics and stuff on this same topic I'll dig up that and post the link so you can have a little better idea of how it comes apart.
Heres the link;
http://www.automotiveforums.com/vbul...d.php?t=642434
Hope this helps !