Harley Davidson low pressure brake light witch

[chuckwp]

Explain low pressure brake light switch. I did not know pressure activated brake switches
have different ratings as hydraulic brake fluid pressure is usually way up there.

[37 Coupe]

Originally Posted by Adam/Mill Valley CA

Lawson, Ron Francis Wiring has a nice low pressure switch:


https://www.ronfrancis.com/category/brake-switches


Adam

I went through two HD switches that were supposed to be silicone fluid proof before I went to the Ron Francis one.It has been working since 2008.

[V8COOPMAN]

Originally Posted by chuckwp

Explain low pressure brake light switch. I did not know pressure activated brake switches
have different ratings as hydraulic brake fluid pressure is usually way up there.

Hey Chuck ....Yup, we sometimes learn new stuff every day. And here's how we know these 'pressure-activated' switches CAN operate differently. There are pressure-type switches out there that will not ALWAYS "light" the lights when you put your foot on the brake pedal. Say that you're driving down the road in heavy traffic. The traffic is moving continuously at roughly 10 MPH. The guy in front of you slows-down just a little, yet enough that you need to slightly touch the brake pedal. Under those circumstances, SOME (if not many) switches will not have had enough pressure applied to cause the contacts to "CLOSE", and thusly, will NOT illuminate your brake light filaments.

I have never taken the time to bust one of these switches apart, but I can imagine a small spring inside the switch that regulates how much pressure must be allowed to close those contacts. And we know that springs can be manufactured to different degrees of resistance. This is a problem that has been addressed by more than one switch supplier. DD
.