Ethan;

Almost all of your issues are likely the result of poor connections...so arm yourself with an enlarged copy of the wiring diagram (maybe this one: http://www.sw-em.com/544%20Wiring%20Diagram.jpg ) tools, some emery cloth, a wire brush, some ACZP* ...and have at it...the overheated lens is likely caused by nothing more sinister than using an incorrect lamp of too high a wattage...this has resulted in extra heat at the light fixture, and the extra current in the circuit isn't doing the switch which controls the circuit any good either...always consider the ENTIRE current path when working on electricals...

Cheers from Connecticut!

*(see: http://www.sw-em.com/anti_corrosive_paste.htm **)

**...while your at your electrical system, check your Brake Light Function! See: http://www.sw-em.com/safety_bulletin_4.htm FULL DISCLOSURE - CAUTION - PLUG FOLLOWS: If you decide you need to upgrade to a Pedal Position Sensing type, and order one from me, I'll include a generous sample of ACZP suitable for the electrical maintenance work.