Pressure Brake switch wiring

[Gmorrone1214]

Hello everyone, I wired up everything on my 79 bobber but I am having some trouble with the brake light.

The way I have it running now the power light is just on and when I compress the brake the light does not go on,

I have the mikesxs banjo bolt pressure switch that comes with 2 wires same color.

I have taillight that came with 3 wires, 1 red, 1 blue and 1 black.

I hooked it up as the picture shows? Is something wrong?

 

[madjap]

Lets see... Cap is 'capacitor' which has replaced your battery/power source, right? If so, a hot wire FROM the power source INTO your pressure switch, THEN a wire OUT of your pressure switch back to your brake light wiring (one of the wires that comes out of your brake light will be brake, one will be tail or 'running light' and the other is likely a ground wire.) Does that help?

 

[Gmorrone1214]

Lets see... Cap is 'capacitor' which has replaced your battery/power source, right? If so, a hot wire FROM the power source INTO your pressure switch, THEN a wire OUT of your pressure switch back to your brake light wiring (one of the wires that comes out of your brake light will be brake, one will be tail or 'running light' and the other is likely a ground wire.) Does that help?

Well as per the diagram/picture what you said is exactly how I wired it up. I just thought something must have been wrong since it was not working, the switch is brand new.
And yes my brakes were bled and I have a working brake.

 

[madjap]

No, your diagram shows you have a power wire going TO the pressure switch AS WELL as back to the brake light (the red T your diagram shows). Where your T shows coming off the Cap, the red line that goes to the right (back to the brake assy) should NOT be there. See?

 

[Gmorrone1214]

In these diagrams the power is T to the tail light and the switch http://www.xs650.com/forum/showthread.php?t=61&page=12.

Where is the hot wire going to the taillight then to power the running light ?

 

[weaselbeak]

A switch just breaks one wire. In other words, you have both ground and hot going to the brake light. The switch is just there to keep one wire, the hot wire, open. When you pressurize it, it closes and completes the circuit, turning the light on. So hot wire to the switch from the lever, and back out to the light.

 

[madjap]

Oh, I thought you were only talking about the BRAKE circuit. I wonder if using the same wire for brake and tail (your red T) would or could cause grounding problems then when you apply the brake? When you turn the key on do you have a tail light? This may sound dumb but make sure it has a double filament bulb too.

 

[Gmorrone1214]

Oh, I thought you were only talking about the BRAKE circuit. I wonder if using the same wire for brake and tail (your red T) would or could cause grounding problems then when you apply the brake? When you turn the key on do you have a tail light? This may sound dumb but make sure it has a double filament bulb too.

Yeah it is a double filament , i put power to the blue wire - switch to brake light - and it lit up.

Idk, I just found a way to check the switch with a voltmeter so I'll do that first tomorrow . If it checks out I'll wire it up with independent power source to switch and to taillight and see how that goes.

I will post finding back up tomorrow

 

[Gmorrone1214]

Okay so I tested the switch and it's functional. Ran the bike tested volts at the return wire (blue) from switch to brake light . 10vollts when I press the lever in - 0 with it not depressed so it's working . But for some reason it's not lighting up the brake light .

I then put power directly to that return wire (blue) and it lights up.

 

[fredintoon]

Hi Gmorrone,
one hot wire to the brake switch then to the brake light filament.
Another hot wire directly to the running light filament.
Both filaments have a common ground back to the capacitor.
If the ground ain't working the running light filament grounds via the brake light filament so you'll get a working tail light until you hit the brake, both filaments see power and the tail light goes out.

 

[Gmorrone1214]

Problem solved thanks everyone.

Posted via Mobile

 

[LuckyLucOnBass]

Reviving this post. I'm having brake light wiring problems. I have my running light working. Out of my tail light, I have three wires. Yellow, Black, and Red. Bulb is also dual filament. I did a drawing of what I have wired for the light. My problem is the brake light. When I turn the key on, it blows the 15A fuse that is running to my brake switch. I checked for frayed or bare wire, but everything looks good. My wiring is bare bones. My fuse block has a 25A main fuse. Then 15A fuses for the headlight, taillight, and brake switch. What the heck am I missing. Once this is done, I can test ride my bike.

 

[weekendrider]

Did you check for continuity to ground? Undo the wire from the switch to the light. Does it still blow the fuse? If so take it loose from the fuse box and check continuity of that wire to the switch.

 

[fredintoon]

Hi Lucky.
Aftermarket lights come wired up funny so you can't trust the colors. Betcha what you think is the ground wire, ain't.
Unplug all 3 wires, set your multi-meter to measure Ohms and check the resistance from each wire and the bike frame.
The wire with the really low Ohms reading is the ground, the middle reading is the brake and the highest is the running light.

 

[LuckyLucOnBass]

Hi Lucky.the
Aftermarket lights come wired up funny so you can't trust the colors. Betcha what you think is the ground wire, ain't.
Unplug all 3 wires, set your multi-meter to measure Ohms and check the resistance from each wire and the bike frame.
The wire with the really low Ohms reading is the ground, the middle reading is the brake and the highest is the running light.

That was exactly my problem at first. It has three colors. Red, black, and yellow. Simple thinking would say black is ground, red is running, and yellow is bright. But it isn't. Yellow is my ground. Red is running. Black is bright.

In the video, I have the ground and running light connected. When I turn on the key, the running light comes on. I get an alligator clip and connect my hi beam to the (+) terminal. That makes the brake light come on. So I need to find out why the fuse is popping. Somewhere between the switch and the actual light might lie the problem?

 

[LuckyLucOnBass]

Did you check for continuity to ground? Undo the wire from the switch to the light. Does it still blow the fuse? If so take it loose from the fuse box and check continuity of that wire to the switch.

Let me dumb this down for me....

You're telling me to disconnect the lead to the switch from the fuse box and check that one strip? If I get a buzz, then I check from the switch to the light? And then the actual switch?

Am I moving in the right direction?

 

[weekendrider]

Yes disconnect the yellow wire at the fuse box. Check for continuity from that wire to the frame. If you get a reading other than "I"(nfinity) disconnect the wire from the switch to the to the tail light. Then check the wire from the fuse box to the switch again. If you now get an "I" then you are good for that section. Check the wire from the switch to the light. I think you may be grounded at the fixture.

 

[LuckyLucOnBass]

Yes disconnect the black wire at the fuse box. Check for continuity from that wire to the frame. If you get a reading other than "I"(nfinity) disconnect the wire from the switch to the to the tail light. Then check the wire from the fuse box to the switch again. If you now get an "I" then you are good for that section. Check the wire from the switch to the light. I think you may be grounded at the fixture.

Dang, I'm a little lost. Ok. I'll get to it when I get home in a bit. Thanks!

 

[weekendrider]

One thing I don't understand is why you are just blowing one not both fuses.

 

[fredintoon]

Hi Lucky,
the video shows that with just the running light filament connected to the bike wiring and the brake light filament not connected to the bike but instead connected to a pigtail, the brake light works properly.
OK then, with the light completely wired as the wiring colors say is right:-
If the fuse pop immediately you turn the key on there's a short circuit in the brake light's hot wire.
Unless the brake switch is misadjusted to be on all the time, that is. Check it out, too.
If the switch works good and the fuse don't pop until you hit the brake there's a short circuit in the wire between the brake switch and the stop light filament.
And if your bike has a front and a rear brake light switch, check both wiring systems, eh?