Front Brake Light has me baffled.

[AJBinVA]

So the brake light comes on with the rear pedal.

I have power to the front brake revoir micro switch.

I also have power to the Y where the front and rear brakes meet. The factory crimp was in bad shape so I re soldered and it looks good. I get power from the front brake switch all the way through the tailight but it still doesn't come on.

But it does come on with the rear brake. The voltage difference is only about .3 volts. Rear brake 12.46 front brake 12.15.

I'm baffled.

 

[AJBinVA]

Figured it out. Bad terminal on the power going into micro switch. Had voltage through the circuit but too much loss I guess too light the bulb. Fixed the terminal and it works great now.

 

[Fire-medic]

I've had good luck w/stuff like that by hooking a continuity tester to the circuit & flexing the line from one end to the other, and eventually you will see the needle drop. An audible sound that interrupts might be easier than looking at the needle.

I've also found that where a terminal crimp attaches, sometimes you get corrosion at that first inch of insulation, so while the connection terminal looks OK, inside the first bit of wire insulation, the wire is gone, and a good tug will break the remaining few strands, or flexing it back & forth will show you that the wire has disintegrated.

 

[AJBinVA]

That's great advice. Exactly what this terminal looked like. Once I pulled back about a 1/4" of insulation I found the broken strands. Continuity seemed good until I bumped the sensitivy on my multimeter and discovered the descrpency.

 

[COP RUNNER]

Yes , had enough volts through the connection but not enough amperage to light the bulb .

 

[COP RUNNER]

I always explain it like this , I could pop the hood on your four cylinder car , put a Fluke meter on
Your battery , leave the headlights on in your car until the meter reads 9 volts , turn the key to start your car and it may crank over slow but it will probably start because the battery has enough amperage to power the starter to crank over the engine .

Now if I take a 9 volt Transistor radio battery and hook it to the same Fluke meter , it reads 9 volts , but it will not even light your glovebox light bulb , let-alone crank over your engine because it doesn't have enough amperage .