Brake Light Switch Q?

[93lx308]

Hey all, another question. I feel dumb on this one, let me explain. The wiring on my 93 mustang is all f'ed up so I'm trying to wire up the brake lights myself, bypassing the factory wiring using the original brake light switch. Seems easy enough, right?

The switch has only two wires going to it, leading me to beleive it is just an on/off switch. So to test that theory, I used a test light and a spare battery on my work bench. I put power in one wire and grounded the other. The light comes on without depressing the switch. Then when I depress the switch, the wires get very hot and smoke like crazy. I changed the polarity at the switch and the same result happened.

Does anyone know how the brake light switch works? Appreciate any help

 

[CarMichael Angelo]

Then when you did that you caused a direct short.

The switch just interrupts signal flow. It can be done with either 12v, or Gnd. One wire goes to one leg of a light, and the other wire goes to one end of that switch, and the other side gets grounded. When your foot is off the brake, the circuit is interrupted....when you step on the brake, the circuit becomes continuous, and completes the ground path for the circuit.

Savy?

 

[93lx308]

Ahh..im an idiot lol so this is an ordinary on off switch. I tried it again this time installing the switch correctly (aka putting the switch on one of the wires) and it works perfect. Thank you!

 

[revhead347]

Set your multimeter to ohms of resistance next time instead of doing all that craziness. Much easier to just do a continuity check than wiring up a battery with a test light and melting a bunch of stuff. A multimeter is around $6 at Harbor Freight.

Kurt