Modern Vespa

I'm trying to resolve an issue with my turn signals. With the old battery, they would work when the bike wasn't moving, then not work until the bike had been on the road for 10 minutes or so. With a new battery, they only work at a stop, regardless of how long I ride.

So I have the bike apart to try to resolve this. The first possible issue is whether this connector goes anywhere. The picture isn't great, but the wires running from it are blue-white and pink. I think the blue-white has something to do with the signal operation, but I'm not sure what. It wasn't connected to anything when I took the bike apart.




If it's fine how it is, what should I check? I've read some posts about the CDI failing, could that be it? Thanks.

The connector with the blue/white and pink wires is unused in a USA model ET4. I'm not sure if it's there for use in other geographies or what purpose it serves. The blue/white wire is the 12V source to the right turn signal. The pink wire is the 12V source to the left turn signal.

Looking at the wiring diagram, I'm not sure that the CDI could have an effect on the turn signals. They look to be isolated from each other. I would suspect the turn signal relay first, then move on to checking the handlebar switch. The fact that the signals work at a stop and not otherwise is perplexing.

-Craig

If you don't have a volt/ohmmeter, obtain a 12V test light (for a few bucks) at the Auto Parts store. Turn signal issues should be simple to solve but without knowing a few key answers (the test light would give) about where power is and isn't all you'll get is a guess. My guess is the turn signal relay has failed but it also could be the turn signal switch. Or a connector isn't connected or is connected intermittently and you've lost power or ground to the circuit.
Edited to link the wiring diagram.
http://www.scribd.com/doc/23744685/Vespa-ET4-Wiring-Diagram

Well, I'll pick up an voltmeter tomorrow and see what I can find out. I didn't notice until I was riding tonight, but the headlight is now extremely dim, although the brights work fine. Thanks for the help.

Alright, I got a mutimeter, and the battery charge looks fine. Where should I go from here?

I assume you are familiar with a volt/ohmmeter, you'll be checking for DC voltage and for continuity (ohms), if voltage is not present. Those are two different settings on the volt/ohmmeter. Some meters have a built-in audible continuity checker, some you have to read the meter. Make sure the meter is in the correct mode before you test any wires or circuits, you don't want to send 12V into a grounded meter lead if the vom is set in the resistance mode.
Consult the wiring diagram. It appears that when you turn on the key, power goes down one of the wires from the ignition switch to feed the turn signal relay. Put meter on dc scale, black lead to ground, red lead to the terminal on the ignition switch that feeds power to the turn signal relay. What you are doing is to verify the ignition switch terminal that feeds the turn signal relay is energized when you turn the key on. If no power, the ignition switch is the source of the problem. If it is getting power, locate turn signal relay, turn on ignition switch, using the dc voltage setting verify there is power to the turn signal relay by grounding the black lead and touching the red lead to the input terminal of the turn signal relay. If no power is present, verify the wire that feeds the relay from the ignition switch is not faulty by using the ohms or continuity function, connect the black lead at the turn signal relay (input wire) and the touch the red lead to the ignition switch at the other end of the wire. I can't tell the color of the wire by the online diagram but it will be the same color at both the ignition switch and turn signal relay end. If continuity can't be verified with that test then there is no connection between the ignition switch and the relay, either the wire is broken or unhooked. If there is power the next step is to turn on ignition switch, turn on left turn signal, if the bulbs don't blink and the relay isn't clicking smack the relay lightly to see if it operates.
Repeat with right side turn signal switch if the left won't work.
Report back your findings, next step is to verify that power is going from the turn signal relay to the turn signal switch.

Ok, will do. One question, the battery was reading slightly above normal, ie about 13v when not running. Is that a problem? Also, the signals always work at idle, so does that mean the relay is working, or does it not matter?

Ok. I think the clue may be that the battery is reading 13v at rest. Second clue is that the indicators stop working when above idle. Put that voltmeter across the battery and if the voltage reads over 14v when you rev the engine, you have found your problem - replace the voltage regulator.

Oh, and that ET4 wiring diagram is for a pre leader, which you don't get in the states. I am fairly sure that there is NO relay and that flasher signals are controlled by the CDI unit.

Alright, I just checked it, you were right. It was reading in the low 16v range at idle

Am I going to damage the battery by leaving it in until the regulator comes? Is it a difficult job to do?

I read the original post again, afraid I led you down the wrong trail. Agreed 16V at idle seems awfully high, should be maybe 14V or slightly above at half throttle where the alternator is putting out maximum charge. The battery can withstand 13.8V to charge but charging for longer periods of time at too high of voltage (16V) will eventually cause the battery to fail.

Your mystery socket is a diagnostic connector used by Piaggio techs.
It connects directly to the CDI unit.