Bravo Turn Signals

Got a '78 Vespa Bravo model with turn signals. When I bought the bike, the front ones were on but the rear ones were disconnected and the electronics in the rear metal "saddlebag" box looked not set up right.

I should get a picture of what's in that box, because I'm not sure what I'm looking at. I've looked at the diagram on page 23 of this . The two relevant parts look to be the Double Zener Diode and the Indicators Electronic Control Device. The two main components in this box are a large metal cylinder (a little bigger than a D-Cell battery) and a black square thing with four terminal posts coming out of it. There's also a red wire with a fuse inline that isn't connected to anything right now. The fuse especially leads me to believe that maybe there was a battery in this model. There's definitely not one in any of the diagrams in that manual, but that's for more recent models.

So the questions are: What are these two components (if they're the diode and control, which is which?) and do I need a battery? If I need a battery, how do I hook it up? Does it charge off the magneto?


Re: Bravo Turn Signals

Wow. So this is REALLY strange.

Whoever hooked this bike up last screwed some things over majorly. For example, if I hook the two leads up to the taillight, the light will go on without being grounded. I measure the voltage across the leads and it reads 15VAC at idle.

And then, if I turn the turn signal switch on, the taillight will blink! If I disconnect the blinker controller (I figured out which it is), the light remains on but stops blinking. It fully cuts out, not just dims like the blinker is shorting something and decreasing the power available to the tail light.

Then, the engine will die if I pull the brake, but the bulb is good and the tail light gets brighter like it should (until it dies). If I ground the leads that go to the taillight, the engine doesn't die anymore, but the light doesn't work.

I'm convinced that there was a battery in here. There's padding and rust spots (like acid ate through the paint) in the rear box. Also, there's two leads that don't go anywhere right now. When I connect them, the headlight gets brighter. That in itself is strange...

So, the wiring on this bike is really messed up. At least the headlight works consistently! I've looked at both the wiring diagrams from and the Haynes Manual. The Haynes one is too simple and the one is too recent so the wire colors are wrong and there is no battery in the circuit. Does anybody have a diagram from the 1978 era for a Bravo with taillight stop switches and turn signals? Or does anybody have a bike like this that would be willing to work through some of this with me? An entirely new wiring harness might be in order, but i need to know how to get it right this time!

Re: Bravo Turn Signals

Matthew Libhart /

My best guess, and this is a guess, is that the cylindrical part is the flasher and the square black thing is a voltage regulator (same thing that a zener was used for). or possible a regular/rectifier in one. Go to and check the electrical section, look at the regulator/rectifier section of "chasis electrical" and the also the turn signal section to see if anything looks familiar. Since you have a fuse, my guess is you had a battery, not much reason for a fuse w/o a battery. If you had a battery, you'd need a rectifier to turn the AC to DC to charge the battery. I think the guys at scooterworks will answer email, maybe a bit slowly, but they'll help.

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