2003 FXDP, (Defender) 4660 miles. ( I bought it used with 2500 miles in April) About a week ago I pulled a blunder, was out riding, came to a stop, put my foot down, too much sand and gravel on the road, slipped and the bike went over on it's side. No damage because I have an engine guard and floorboards. Tip over switch did it's job and stopped the engine. I got it upright, turned off both the kill switch and the ignition switch. Then turned it back on, she started right up, and off I went. Came home from the ride, and can't really remember if the kill switch worked, but I shut it down and think I would have noticed if the kill switch didn't work.
So about a week later I came back from a ride, hit the kill switch, and nothing....it did not kill the engine. I turned off the ignition switch and killed the engine. So I think, bad kill switch. Went to local dealer, they had the assembly in stock, I buy it and then today I replaced the old assembly with the new assembly.
Guess what, the new kill switch will not kill the engine either!!! Any one have any idea what's happening here? The tip over switch? I can't figure it out. Bike runs great. The only issue is the kill switch won't kill the engine. Help?

 

I don't have a wiring diagram for your bike, but would suspect that the kill switch triggers a relay. I would try and determine which one and replace it.

 

Thanks, finally an answer, I appreciate this help.

 

OK, problem solved. Relay checked out OK. I start thinking about when the bike tipped and I notice my right rearview mirror is too low, and I can't get it right. Sooo, I check everything, start tracing wires etc. Nothing loose. Then I take off the right side switches and brake lever assembly. There it is, when the bike was uprighted, the housings shifted and pinched the wires. I had a short right where the housing pinches and attaches to the bar. Gave the wires the once over, and find two wires shorted. Seal them up, put it back together, replace the blown fuse, and problem solved.
I don't know if anyone else thinks this squeezing the wires to clamp on the switch and brake housing is a poor design, but I sure do.