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GP150 6v points to 12v electronic

Posted:
Tue Jun 27, 2017 7:15 am
by Aalborg Lambretta
I've got a 1970 GP150 battery version running on the original 6v points, and I'm planning to upgrade it to 12v electronic, with a battery PX regulator.
Am I right in thinking I can fit a standard 12v electronic kit, change my bulbs to 12v, change the battery to 12v, add a fuse from the battery to the loom and that will run ok, 'as was', i.e. the horn, parking light and brake light will run off the battery, main lights still run of the AC - but now 12v?
I've got most of the parts lying the garage that I'd need to do this, I'm not looking to go 'full DC' or splash out on a Wassell kit or anything.....
Cheers,
Alan
Re: GP150 6v points to 12v electronic

Posted:
Tue Jun 27, 2017 8:59 am
by Tractorman
Sounds about right but not sure about the PX regulator bit. I used a ac regulator with an dc outlet that keep a battery charged for brake light and accessory use.
Re: GP150 6v points to 12v electronic

Posted:
Tue Jun 27, 2017 9:23 am
by CHRIS in MARGATE
You will need a 5 pin regulator
Re: GP150 6v points to 12v electronic

Posted:
Tue Jun 27, 2017 10:34 am
by Aalborg Lambretta
Yep, that's what I've got, but should I use a 7.5 or 10 amp fuse?
I'm a bit con-fused about that. Only running the horn, parking and brake lights so the trickle charger on the regulator should be enough....I think.
Re: GP150 6v points to 12v electronic

Posted:
Tue Jun 27, 2017 12:35 pm
by Knowledge
I recall that the 5 pin regulators require power from the batter in order to work. If the battery goes flat, the regulator won't work, and there is no way of recharging the battery without resorting to an external power source.
As Tractorman says, there are alternative units to provide power, and I would put the Vespa unit somewhere near the bottom of any such list due to the need to maintain a working battery. However, if used correctly, it is a reliable unit.
Re: GP150 6v points to 12v electronic

Posted:
Tue Jun 27, 2017 12:37 pm
by Warkton Tornado No.1
The answer might be calculable but for all that, I tried 5 amp fuses on my points based, Lucas rectifier & Zenner, 12 volt conversion & they kept blowing.
I went to 10 amp & have not 'cooked' the battery yet, five years on.
'Suck it & see' if you have the 7.5 amp fuses to hand. Of course, not all fuses are 'equal' in that some are more tolerant to surges, but I would advise you to keep an eye on the battery if you go 10 amp 'common or garden' Maplin fuses as I have.
Re: GP150 6v points to 12v electronic

Posted:
Tue Jun 27, 2017 7:44 pm
by sunrisemac
check this out, it might help, it helped me a couple of years ago
http://www.ilambretta.co.uk/12v.html