My 1989 FLHTCU has 12v at the battery & the post on the starter, but drops to 11v at the ign switch. Lights & ign are turned on, but engine has not been started. It also drops another volt thru the Ign Sw, so I know I need to replace the switch (only 10v going to the lights). The guy who sold it to me had run an air horn thru the Ign Switch instead of using a new relay circuit and ruined the Ign Sw. The only thing the wiring diagram shows in the circuit from the starter post to the Ign sw. is a 30amp CB (circuit breaker) marked "Main". 'Seems to me a 1v drop across a CB is too much. Anyone know where this CB is & how do I get to it? It's not under the seat or in either side panels, so I'm guessing it might be somewhere in the fairing??? Am I right? If so, where in the Fairing is it and how do I get to it to check and/or replace it? If I'm wrong, please send me in the right direction.