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Vespa 1981 P125X - NO Battery

Hello all, i have a persisting issue with my light system.

1. Only front flashers work not rear. Checked out all wiring to and from finding continuity throught including ground.
2. When i turn headlight on it flashes along w the brake light instead of stayin on continuosly.

I replaced all electrical to include viltage refulator, flasher and ignition coil. Still nothing.

I placed my cowls on a different bespa and worked fine, so i know bulb and cowl wiring is ok.

Pic shows the wiring behind the headlight. I wonder if its wired wrong causing it to work erroneously. I can send more pics if needed.

What else havent i tried. Thank you all in advance for reading.
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Hooked
PX150E
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On your photo, the 2 prongs behind the headlight bulb seem not to make contact with the bulb, and also appear quite corroded.
You should try cleaning their contact faces with sandpaper, and then bending them down and toward the bulb to make firm contact with the bulb.
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I replaced the headlight electrical socket. Problem persists. Is it possible that i have wired this wrong.
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V-

https://www.scooterhelp.com/electrics/pages/VNX1T.p125x.html#nobattery

Im using this wiring diagram to compare things. Your headlight wiring looks fine. Can you confirm you only have one blue power wire coming off your stator to power all bulbs?

Second, do you still have your old voltage regulator? Did you wire your new one exactly as the previous one?

Third, did you ensure the ground (earth) wires are connected to the spring loaded cowl latches?

Please report back.
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1. Only one blue wire coming from stator
2. Voltage was recently replaced
3. Yes i checked for continuity w OHM meter.

The electric coil behind engine only has one green wire going to it and the sprk plug wire coming out of it going directly to plug.

Thank you
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I have two new questions based on that image.

1. Did you ensure that the black ground wire going off your regulator terminal also touches the regulator body? (See picture)

2. What is the condition of that green wire coming off the regulator? Is the insulation brittle or weak?

In the United States, we have a problem with the green wire in the harness. It becomes brittle and broken faster than any other color. We call it "the Green wire of Death!"
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Yes the black/ground wires are connected with each other. (Plz see foto)

Green wire feels fine and has continuity w ohm meter.
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Hooked
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How are your connections on the HI/LO beam switch? No mention of that in your posts.
Do you receive 12V AC at the socket connections?
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If you disconnect the green wire from the regulator, that should eliminate the turn signals and the brake pedal switch/ brake light from the equation. If you do that, do you still have issues with the headlight, parking light and horn (yellow wire)?

If no change, then I'd start looking into the yellow wire and see if theres any voltage drops in that.
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There is a short circuit to ground in or near the indicator switch. If yours is a euro non battery model the indicator switch is gear side. The switch cable wears heavily with the gear changing. Take the switch out and have a look.
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Hi all,
Should i be getting continuity from white wire on flasher with:
1.white wire on headlight sw.
2. White wire on headlight socket

Two points indicated in foto
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1. No
2. No

Print out a color copy of the wiring diagram from the link I provided earlier. That will help you troubleshoot
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But yet it does. But only when the two black ground wires are connected to the back of the headlight socket and the left turn signal is activated.

With black wires disconnected continuity only existed between the flasher white wire and white wite behind the turn signal sw.
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Vesuvio1971 wrote:
But yet it does. But only when the two black ground wires are connected to the back of the headlight socket and the left turn signal is activated.

With black wires disconnected continuity only existed between the flasher white wire and white wite behind the turn signal sw.
Thats perfect. That means the white wire from the flasher is good and not shorting to ground.

When you connect the 2 grounds, the path through the white wire goes through the bulbs and then to ground, giving you that reading.

Since you said your rear signals arent working, I'd try putting one probe of your meter on the white wire coming off your turn signal flasher and the other probe at the rear cowl contact. Testing for continuity, turn the left and right turn signal switch and see if your meter shows continuity. It should. Test both sides. If both are working, test continuity from the green wire from the regulator to the flasher relay. That should show good continuity through the wire and nothing to ground (when disconnected).
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Not sure if I'm tracking, is this how/what i should be cheking for continuity. Or Should the white wire remain connected to the flasher or this test.

The green wires all have continuity
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Looks perfect. You want to test

1. The wire has continuity in general
2. The wire does not have continuity to ground when disconnected.

If 1 fails, it means your wiring is broken/cut etc and there isn't a pathway for electricity to go.

If 2 has continuity to ground when disconnected, you have a short and you are mildly losing voltage or the big one, shorting out that circuit and anything else associated with it!

Does your wiring and switch work as it should? Nothing shorting out?
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If all continuity test check out it's time to checkt ac voltage. I think that switch is bad or something is grounded wrong.
The flow of power goes from the stator to the right switch via a blue wire that powers horn and everything in the headset except the signal indicator. The yellow wire moves power to the regulator that powers the turn signals components and rear brake light.
With the motor running and stuff flashing, start testing for 12 Volts AC. Check the yellow wire still plugged into the regulator. Should have around 12 volts or more going into regulator and around 12 volts or less coming out the green wire. From there check the right switch wires using the diagram above. Voltage should go up and down as headlights and brake light flash incorrectly.
You're chasing the voltage to see where it drops to pin point the problem.
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1981 P125X - no battery

Sorry for the absence. Back at it again. I decided to pull out the entire wiring harness today. Any suggestions where to obtain a new harness.
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