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Using original loom

PostPosted: Sat Nov 14, 2015 2:48 pm
by Scooter Paul
I'm converting my series 2 to electronic. The loom is original and the scooter is a battery model. I want to power a 12v battery. The brake light switch is the 3 hole type. Am I right in thinking that I connect the red and grey wire in the loom to B+ on the regulator to trickle charge the battery and run the brake light and horn? Shall I also connect the brown and purple to G on the regulator to run the lights? Shall I connect the purple to the brake light switch bearing mind that the battery is also powering the brake light? I'm happy for the lights to be AC so I'm not looking for a full DC system I just want a battery for a single spot and DC brake light and horn would be a bonus. Ta for help.
Paul.

Re: Using original loom

PostPosted: Sat Nov 14, 2015 5:14 pm
by Captain Pugwash
Post mod I think the grey in the loom that comes up from the rear junction box/rectifier powers the horn, the grey is also junctioned in on the three hole rear brake light before going up to the headset.

So I'm thinking post mod if you want to keep the horn working on dc along with the brake light you would probably need to connect three wires (red grey and purple to the trickle charge) and just the brown wire to the ac side.

This should also leave the side lights/parking lights connected to the dc circuit as it was originally wired up when using the old 6v rectifier and battery.

But there are two different dc wiring circuits for the series 2 early and late and I think it has somthing to do with the horn and which wire it takes its feed from.
I might be wrong

Re: Using original loom

PostPosted: Sat Nov 14, 2015 5:55 pm
by Scooter Paul
Captain, thanks. The connection for the purple wire is the bit that has me puzzled. Since posing the question I have done a Google search and Cambridge Lambretta say red and grey and brown and purple connections. Still leaves me wondering that you might end up with both DC and AC power going to the brake switch. Is this a problem?
Paul

Re: Using original loom

PostPosted: Sat Nov 14, 2015 6:09 pm
by Captain Pugwash
Scooter Paul wrote:Captain, thanks. The connection for the purple wire is the bit that has me puzzled. Since posing the question I have done a Google search and Cambridge Lambretta say red and grey and brown and purple connections. Still leaves me wondering that you might end up with both DC and AC power going to the brake switch. Is this a problem?
Paul


I can't recall how the 3 hole brake light switches power, if all three wires join when the pedal is pressed or just purple and pink. And the third hole is used just a junction but that wouldn't make sense otherwise why would the grey junction there.

The original rectifier taps power from different parts on the original 6v dc rectifier to feed at different amperage feeds to the grey and purple, but I think it's most likely because the two circuits grey and purple are used together to supply power to the brake light.

It's a long time since I have used a three hole brake switch on anything other than a full dc conversion.

But as I said I might be wrong.

Hopefully someone else will chip in and offer some better advice

Re: Using original loom

PostPosted: Sat Nov 14, 2015 6:21 pm
by Scooter Paul
The brake switch does connect pink purple and grey together.
Paul.

Re: Using original loom

PostPosted: Sun Nov 15, 2015 12:01 am
by ToBoldlyGo
For what a new loom would cost surely you'd be better off doing that rather than sticking with old wiring that may cause trouble down the line.

Re: Using original loom

PostPosted: Sun Nov 15, 2015 8:48 am
by Scooter Paul
ToBoldlyGo wrote:For what a new loom would cost surely you'd be better off doing that rather than sticking with old wiring that may cause trouble down the line.

A reasonable comment but this loom is in excellent condition so it would be a waste not to reuse it.
Paul