Electrics

[ChrisTheChippy]

Ok here we go.
I have absolutely no clue about auto electrics my way of testing things is to wiggle the wires and hope for the best !
So can someone please explain to me the difference between positive and negative earth ?
Absolutely simple terms please .
Who's that sniggering at the back ?
Cheers Chris

[Mick D]

Hi

Have a look at the battery on your bike - one terminal will most likely have a length of wire going directly to either the frame or engine, this is the battery earth wire and if it's on the -ve terminal your bike is negative earth, likewise if it's on the +ve terminal the bike is positive earth.

The convention adopted, +ve or -ve earth, will have an effect on how polarity sensitive components, rectifier, coil, capacitor etc. are connected.

Regards Mick

[SPRIDDLER]

Wot Mick D said.
But if you want to go into more specific detail about Lucas electrics there's an excellent fairly simple guide here:

https://matchlessclueless.com/electrical/

[spookefoote1956]

May I ask what your bike(s) is / are?

[SPRIDDLER]

As per Chris's Profile maybe?

http://www.jampot.com/forum/memberlist. ... e&u=116129

Whichever bike it is, the principles are the same.

[Plugsnpoints]

I converted my house to positive earth.

It's not safe though-I have to wear marigolds and wellies when I do the washing now!

[SPRIDDLER]

I converted my house to positive earth.

It's not safe though-I have to wear marigolds and wellies when I do the washing now!

Titter ye may, but many years ago I interviewed an ex RAF electrical engineer for a sales job. He admitted he was colour blind so for H&S reasons they insisted that when at his bench he stood on two rubber mats.

[spookefoote1956]

Spridds you are naughty.

Is there something in particular you wanted to do Chris?

[spookefoote1956]

Many British motorcycles were built with the wiring positive earth. You may have noticed that modern motorcycles seem to be, in the main negative earth. In my case, and probably yours, the dynamo can be re-polorised to be either positive or negative with great ease and the minimum of skill. The regulator may need some attention but again this is simple.

The main reason for altering from positive to negative earth for me would have been the availability of LED bulbs. However this is no longer an issue as positive earth bulbs are readily available.

Electrickery used to be a dark art to me too but through asking questions I have managed to make looms for both the Beast and the Cub.

Cheers, Chris

[clive]

...The regulator may need some attention but again this is simple.
Cheers, Chris

Given that the CVC unit is wired to FADE (field, ammeter, dynamo and earth) I was wondering what attention it might need when converting from positive to negative earth.