AC to DC
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Member
Vespa T5 251, Lambretta GP200
Joined: 27 Jul 2019
Posts: 40
Location: Leeds, England
Thu Apr 01, 2021 3:07 am quote
I'm not really too clever when it comes to sparks. I bought the SIP Vape sport DC for my mk1 T5 because the EGT gauge needs a DC supply.
I don't want to fit a battery even though I have a suitable one if need be. I've got a DC horn and indicator box to go in.

Can I just feed one of the red DC outs into the loom and disregard the other DC out?

Wires is wires? Thanks v much for any replies.
Member
Vespa T5 251, Lambretta GP200
Joined: 27 Jul 2019
Posts: 40
Location: Leeds, England
Thu Apr 01, 2021 4:33 am quote
Only 1 red out, my bad.
Ossessionato
76 Sprint V, 63 GL, 62 VBB, 05 Stella
Joined: 16 Jun 2011
Posts: 3187
Location: Nashville
Thu Apr 01, 2021 4:58 am quote
If you look at the wiring diagrams that came with the installation guide for the Vape, on page 4, you can effectively cut out the battery loop and shift the fuse inline from the stator.

The key thing to be aware of is that you need to keep your AC ground (black ground) and DC ground (brown ground) separate or you'll kill the flywheel.

From there, it's red wire out of the regulator into your existing wiring harness, wire up the kill switch (normally green in the harness) to the blue-white off the CDI.

Check out This thread which has extensive discussion of the topic.
Member
Vespa T5 251, Lambretta GP200
Joined: 27 Jul 2019
Posts: 40
Location: Leeds, England
Thu Apr 01, 2021 6:30 am quote
Thanks CM. I've already read that thread but I am too simple! Thanks for the tip about the earths but even that has me scratching my head. They all earth to the frame anyway so aren't they sorta connected?
Ossessionato
76 Sprint V, 63 GL, 62 VBB, 05 Stella
Joined: 16 Jun 2011
Posts: 3187
Location: Nashville
Thu Apr 01, 2021 6:41 am quote
RunsLikeSlug wrote:
Thanks CM. I've already read that thread but I am too simple! Thanks for the tip about the earths but even that has me scratching my head. They all earth to the frame anyway so aren't they sorta connected?
You need to isolate the earth between the regulator/rectifier and the stator (the black ground in the diagram). That's the simplest one since it's the one direct wire.

The ignition ground is yet another ground and we don't talk about it
Ossessionato
1979 P150X, 1983 P200E, 1988 T5, 1995 PX200E, 2011 Yamaha Fazer 600 S2
Joined: 02 Aug 2015
Posts: 2257
Location: Veria, Greece
Thu Apr 01, 2021 8:58 am quote
@CM: I know we've discussed this before, but even SIP's & VAPE's directions show a common ground for both. Same goes on my P although with a Ducati ignition. Is there a chance your LML harness is different or the flywheel was "killed" through voltage returning from the starter's safety / clutch relay??

@RunsLikeSlug: FYI, you'll lose the tachometer. It needs a regulated 12v AC "pulse" to work. Careful sending DC to the "old" AC line. SIP sells the VAPE for the T5 classic (no tacho)...



Ossessionato
76 Sprint V, 63 GL, 62 VBB, 05 Stella
Joined: 16 Jun 2011
Posts: 3187
Location: Nashville
Thu Apr 01, 2021 9:09 am quote
SaFiS wrote:
@CM: I know we've discussed this before, but even SIP's & VAPE's directions show a common ground for both. Same goes on my P although with a Ducati ignition. Is there a chance your LML harness is different or the flywheel was "killed" through voltage returning from the starter's safety / clutch relay??
I used the common ground from the AC Ground out of the stator to the regulator, which is what I think killed it. Isolating that seems to have fixed the problem, hence my belief that it's the "right" way to do it, rather than actual understanding of the underlying engineering.
Hooked
Vespa PX200
Joined: 27 Jun 2010
Posts: 430
Location: Belgrade
Sat Apr 03, 2021 9:42 pm quote
Hey Chandlerman, where specifically did your separate ground connections hook up to the frame? Just curious how you did it.

Like many, I loathe wiring. Instead of understanding the underlying science I prefer to ape the implementations of others.

Speaking of which, one thing I'd also love is a "Run the AC pulse signal to the SIP Speedo for Dummies" guide. If anybody's got one.
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2238
Location: california
Sat Apr 03, 2021 10:05 pm quote
Jim - I couldn't get a proper signal without all sorts of interference from my VAPE to my SIP speedo - so I went to this to stop it bouncing all around.
It has been flawless since.
https://www.sip-scootershop.com/en/product/rev-signal-filter-koso-sip-rev-counter-speedometer_KOBA0040?q=Kosovo%20signal
Hooked
Vespa PX200
Joined: 27 Jun 2010
Posts: 430
Location: Belgrade
Sun Apr 04, 2021 1:34 am quote
Hey Charlieman, thanks for the tip. So how does this work -- the business end of it clamps on to the HT cable somewhere? Like a timing strobe?
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2238
Location: california
Sun Apr 04, 2021 7:18 am quote
Yes - exactly.
Seriously - the brown wire from speedo to white wire on CDI thing that SIP says "sometimes works" was absolutely useless to me.
In their own fine print after they state that - they say you may need a Koso like filter - which... I did.

Just clamps to HT. I made a new clamp top out of a piece of sheet metal - because Koso's clamp seemed to be designed for about 12 gauge wire. I made it with tin snips in about 20 seconds, bent it by hand around the HT lead - and haven't thought about it for a year.

It will fix your rev counter demons if you are experiencing them.
Member
Vespa T5 251, Lambretta GP200
Joined: 27 Jul 2019
Posts: 40
Location: Leeds, England
Sun Apr 04, 2021 10:02 am quote
There must be a reason for Piaggio to have run copper from the stator to just earth near the V reg...I don't know why but if they could have saved copper they would have I think.
A mate with a Lammy wrapped the AC feed for the SIP speedo around the HT lead a good few times and the tachometer works. That did not work on my Lammy!
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