switch is secure and i here the click when i pull the lever. I had the rear wheel off today(nail in the tire). Maybe i could've hit something. i took the seat off and the connection to the light seems alright. i'll have to break out the meter tomorrow.BTW How is it i seem to get you two guys lately?
Before you go crazy tearing things apart trying to locate the problem, try this: I was ticked because i thought my light wasn't coming on when I squeezed the front brake. Try squeezing it REAL hard, like you were coming to a hell of a stop. I know this sounds simple, but it might be it. I noticed with my 620, a tiny bit of pressure on the rear brake will turn the light on, the front brake has to be squeezed almost as far as it'll go to turn on the brake. Hope this helps.
Since you said you took off the rear wheel - are you sure that the brake light is not on even when the brake lever is not depressed? I am just wondering if you might have mussed something up with the rear brake when you replace the rear wheel. The rear brake lever can easily go out of line from depressing the rear brake light "switch".
Basically, when mine was mussed - I just checked all of the connections and "switches".
I just found the same problem with my 99 M900 City when I was changing the oil. Radio Shack had the switch. You have to cut off the lever, and solder the wires to the two outer poles so the switch is closed when the button is released, and open when depressed. It works great and I saved $40.00 over the dealer price.