Modern Vespa

I need to install a brake light switch and wire it in. The motor is an 83 px125e. Can I tap into the tail running light wiring for power? Where do I need to fish the wire to..or from..or through or over or under??

I figure I need to find power, go to the switch, go to the lamp and then to ground.

Thanks!

I'd like to see someone chime in on this because I can't seem to get my rear brake switch working on my P200.

Your wiring harness isn't designed for a rear brake switch? I thought that was on all P's, US and European.

well, i can't very well tell you how to wire it until you tell me how the brakeswitch is operating... normally closed or normally open.

That little plunger on a brakelight switch is by default pushed in... which on most non-battery bikes is BREAKING the circuit. When you step on the brake, the little plunger comes out, and it COMPLETES the circuit, allowing the juice to flow through to the taillight.

Typically, on a modern non-battery harness, the brakelight circuit is it's own wire coming off of the main power lead that runs up to the headset...so, it would split off right before the rest of the wires run into the switch at the headset. Then it would run back down the harness and into the brake switch. Then, another wire would lead out of that and back to the brake light ( use blue if you don't want to confuse folks ).

My Bad...and I've been out of town for awhile. Bastards have been making me work for my money!

This motor is in a 67 GT, no battery

I need to wire a switch in because...well there isn't one.

I do have switch from Scooterworks that is supposed to be for Older Vespas, no battery.

Usually a blue wire from the stator splits at the junction box, one goes to the brake switch and from there a grey (or black) wire goes to ground, the spilt blue goes to the brake light bulb, and a black wire from the bulb goes to ground.

It might be slightly different if you have a regulator set-up, in this case the blue from the stator goes to the regulator and from there a grey goes to the brake switch. From the switch another blue then goes to the brake light. Then from the brake light a black wire goes to ground.

You don't say if its on the pedal or lever????

Alright...i'm going to make some assumptions, and give you directions based on that.

It's an 83 PX engine, so you're likely running your electrics off the stator into a 12v regulator. All of your circuits from your GT likely tie together at the output of the regulator, where before they each had their own independent circuit that had a dedicated coil on the stator.

From the regulator you need a wire that runs up to the brake switch, soldered to one of the contacts there. Then you need another wire that runs from the brakeswitch back to the tailight ( soldered at one end to the other metal contact ), and then run back and connecting to the brakelight bulb. The other side of the bulb grounds to the frame.

That's it. It's a simple circuit. Regulator to brakeswitch, brakeswitch to brakelight. Choice of bulb should be 12v, 10watt....which is either a festoon or a bayonet style depending on the taillight housing you're running.

Well it only took a year but I did the install today.

You called it Eric. As you guessed all the electrics off the stator into a 12v regulator, which needed replacing. All the circuits were tied together at the output of the regulator in a real mess.

The wiring on this thing really was a mess. The junction box wouldn't close because there were so many splices there. I pulled the tail light and the tank and there were some wires that were capped off.

I started back at the source and cleaned up all the splices, used proper connectors and solder. I used the black switch. With the pedal in the non-brake position the plunger is depressed and the circuit is open.One of those wires in the tank was hot. I fished two wires back from the switch, tied one into the hot and the other to the brake light.

Popped in the bulbs, reinstalled the tank (I'm pretty quick at getting that in and out now!) fired it up and stepped on the brake. SWEET..nice bright brake light!

I don't have a problem not having directionals...but I always worried a little not having a brake light!


Thanks for the help all! You guys and gals came through again!

Oh yeah...I did use blue wire!