Allen Banks recent post on his brake light problems and the resulting brake light switch discussion that resulted is what prompts this post on my "thoughts" ref brake light switches:
I recently bought an enclosed car hauler trailer, and the electric trailer brake controller I now have is the cause of my "thoughts" about brake light switches:
I just barely understand how this thing works, but I know that it includes some kind of a little "pendulum" inside that is very sensitive to any change in the forward motion of the tow vehicle. Because it works so well, and is so reliably responsive to any degree of slowing of the tow vehicle, I just wonder why the same type sensing device could not be used to activate brake lights instead of the electric trailer brakes,....??? Probably possible but too costly? But then again, this whole trailer brake controller is available nowadays for just over a hundred bucks! Just a thought,.....harold
The idea of the pendulum control that is used with a trailer is to give you more braking if you need it because the vehicle has more momentum when it has more speed. If the vehicle is just barely moving the trailer brakes may not be applied at all or very little since they are not needed. That control if applied to a light would give you a dim light or none when you have applied the brake pedal at low speed but that is not the purpose of the brake light switch. The brake lights are supposed to signal instantly and brightly when the driver has applied the brake pedal with his foot. It is more than anything a WARNING to alert you that the driver sees a reason to slow down. You may not know why but you instinctively will move your own foot toward the brake pedal when you see that light. The brake light switch needs to be totally reliable and fast acting to give you a true switch ON when you need it to warn folks behind you. In a T if you are going to get in an accident most likely you are going to get hit in the rear so light it up brightly. A trailer brake controller is a sophisticated "proportional" control that applies the trailer brakes power proportionately to the need that the conditions dictate.