[T3] DOT 5 and brake light switches

[Sean Bartnik]

I was doing some online research today on this topic and found some other stories from people whose cars use pressure-activated brake light switches about those switches failing after use with DOT 5. Porsche of course but also the same experience with MG owners. 

I read on a Porsche 356 forum where a guy's brake light switch failed two days after switching to DOT 5. He calls up the shop he bought the brake stuff from and they tell him to use a Harley-Davidson brake light switch. He does, and it works great. 

So I dug into that, turns out HD specifies DOT 5 for their bikes and they use the same type of pressure-activated switches that we do, apparently even the same thread (assuming Porsche 356 and ours are the same).  Also apparently every big twin and sportster since ~1971 use the same switch so they are easy to come by. 

Perhaps this will be my next experiment when/if my FTE switch dies. 

Sean