OP
UTC

Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
 
Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
UTC quote
So I have px125e.
Swapped in a p200 engine.

All lights work minus the headlight (top bulb) and the horn.

When I start flipping switches, the bottom light turns off and the large bulb lights up bit only when i rev the throttle. It's nothing noteworthy but it does light up a tad.

The horn gives me nothing. It's dead.

Any idea what I could be?

Could it be the bulb?
Do I need a new horn?
Could it be the rectifier?

Any tests I can do to narrow it down?

The battery is brand new.

Thank you.

N
@garncarz avatar
UTC

Molto Verboso
1964 Allstate Cruisaire, 2022 Husqvarna Vitpilen 401, 1972 Suzuki T500J
Joined: UTC
Posts: 1076
Location: York, PA (the intellectual center of the universe)
 
Molto Verboso
@garncarz avatar
1964 Allstate Cruisaire, 2022 Husqvarna Vitpilen 401, 1972 Suzuki T500J
Joined: UTC
Posts: 1076
Location: York, PA (the intellectual center of the universe)
OP
UTC

Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
 
Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
UTC quote
garncarz wrote:
https://www.scooterhelp.com/electrics/pages/VNX2T.px125e.html
https://www.scooterhelp.com/electrics/pages/VSX1T.p200.html
Grounds are good. Switches intact.
@chandlerman avatar
UTC

Lucky
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 66 Lammy S3
Joined: UTC
Posts: 10800
Location: Nashville

252 Days Since Last Explosion
 
Lucky
@chandlerman avatar
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 66 Lammy S3
Joined: UTC
Posts: 10800
Location: Nashville

252 Days Since Last Explosion
UTC quote
Isn't it a split AC/DC system? Sounds like something is crossing over between the DC (pilot light/turn signals/brake light) and AC (headlight/tail light) sides of the electrical system, maybe.
OP
UTC

Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
 
Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
UTC quote
I have no idea.

Electrical issues elude me. I am honestly at a loss. Hence why I'm here asking. I'm hopeful someone has experienced this and solved it.
@sdjohn avatar
UTC

Johnny Two Tone
'15 GTS300, '86 PX125EFL, '66 VBB, '01 ET4
Joined: UTC
Posts: 8981
Location: San Diego, CA
 
Johnny Two Tone
@sdjohn avatar
'15 GTS300, '86 PX125EFL, '66 VBB, '01 ET4
Joined: UTC
Posts: 8981
Location: San Diego, CA
UTC quote
yeah headlight and horn are on the ac side of things
OP
UTC

Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
 
Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
UTC quote
sdjohn wrote:
yeah headlight and horn are on the ac side of things
Ok. So what does that mean in respect to diagnosing or resolving my issue?
UTC

Hooked
PX150E
Joined: UTC
Posts: 257
Location: Florida, USA
 
Hooked
PX150E
Joined: UTC
Posts: 257
Location: Florida, USA
UTC quote
When you swapped to the P200 engine, did you transfer the stator from your 125E to the 200? I am pretty sure you need that stator for everything to work properly as before. The battery powers the horn, brake light, neutral light, and tail light (if your ignition switch has a parking position).
@garncarz avatar
UTC

Molto Verboso
1964 Allstate Cruisaire, 2022 Husqvarna Vitpilen 401, 1972 Suzuki T500J
Joined: UTC
Posts: 1076
Location: York, PA (the intellectual center of the universe)
 
Molto Verboso
@garncarz avatar
1964 Allstate Cruisaire, 2022 Husqvarna Vitpilen 401, 1972 Suzuki T500J
Joined: UTC
Posts: 1076
Location: York, PA (the intellectual center of the universe)
UTC quote
sp949 wrote:
When you swapped to the P200 engine, did you transfer the stator from your 125E to the 200? I am pretty sure you need that stator for everything to work properly as before. The battery powers the horn, brake light, neutral light, and tail light (if your ignition switch has a parking position).
Forum member supplied image with no explanatory text
OP
UTC

Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
 
Hooked
'81 Vespa P200e, '85 Vespa PX125e, 1985 T5
Joined: UTC
Posts: 369
Location: St. Catharines, Ontario
UTC quote
sp949 wrote:
When you swapped to the P200 engine, did you transfer the stator from your 125E to the 200? I am pretty sure you need that stator for everything to work properly as before. The battery powers the horn, brake light, neutral light, and tail light (if your ignition switch has a parking position).
I installed the stator that came with the p2.
Everything works. Minus the horn and tip headlight bulb.
@spacecat avatar
UTC

Hooked
Vespa Primavera 1974
Joined: UTC
Posts: 225
Location: Nebraska USA
 
Hooked
@spacecat avatar
Vespa Primavera 1974
Joined: UTC
Posts: 225
Location: Nebraska USA
UTC quote
Take these two items out and test them separately. They may both have failed or they may have different causes of failure.
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