Wiring Loom Help

[Royalratch]

Hi all.

Once again I find myself in need of forum wisdom. Probably an easy question but I'm going to start making my loom from scratch for my build based on the diagram I've drawn up I wondered of somebody could fell me what gauge cables I should use for what as I'm not 100% up on what the load for each cable is?

Any other tips / correction / suggestions most welcome!

[Ginger Bear]

i pod charger

[CB 750 FAN]

Elecrtic shaver or beard trimmer.

[Royalratch]

Come in dudes - 2 replies and both are digs!

Its actually an iPhone charger as I will have amount up front for it which will have a GPS based Speedo and Nav.

I will probably run a 12v supply right off the battery tho.

Any help in the initial question lol...

[Ginger Bear]

Sorry Ratch.

Friday night after a long week and all that.

This should be of much more use to you!

http://www.vehicle-wiring-products.eu/V ... inwall.php

[Royalratch]

Thanks GB - tells me what cable gauges take what loads but not what loads each circuit on an average bike loom require?

Starter Circuit - 40amp?
Lighting - ?
Charging - ?

Anything else?

Earth cables should always be equivalent or greater gauge than the positive of same circuit?

[Serps]

I guess it just a matter of doing the maths

ie: the brake light is 21 watts so needs a cable that can carry 21watts/12 volts so less than 2 amps. 0.5mm gives you 11 amps so for most off the loom this should be fine and will give you upto 132 watts.

Earth cable should = the load, but if you are using a single earth and teeing of it then the spine should = the total load so may need to be bigger. maybe go for the 1mm (198 watts)

Sorry don't no what the starting or charging watts/amps are but

VWP smallest starter cable is 110 amps which i would have thought would be adequate.

charging from memory doesn't look that big a cable (the 3 yellow ones) 1mm will probably do or 2mm will be over kill.

[Ginger Bear]

Ratch, Put simply, divide the watts, by the volts (12 in this case) and it will tell you how many amps will be drawn through the cable.



V=IR (Google it)

[Taffus]

Volts(V)= Current (I) x resistance (R)
Power W (Watts) = I2 x R (where I is squared)

Theory here
Made easy here

[PAULJAC47]

Like being back at tech

[Royalratch]

Cheers lads.

Still need to know what each part draws on this particular bike / motor but I'm sure I can track that darn.

Thanks!

[Taffus]

each part will have a voltage V (in this case we can assume 12V) and watt W usage, you can add the watts for each circuit and then workout the current for that circuit
Lets say the max your head light needs is 60W (low beam 55, high 60) then

[Al]

Just bought a load of wire from VWP.
It is Ref 25. 28/0.30mm, 2mm2, 25amp
http://www.vehicle-wiring-products.eu/V ... inwall.php
Its to alter the (mainly) ignition side of my J harness.
This size of wire is the same approx size as the wire that carries the highest current on the original loom where the fuse rating would have been 25 amp if i remember correctly.
Its' narrowly larger to the eye and i dont think it represents an issue to work with except when adding two or more cables to a single connector.
It is the next size up from 90% of the wire in the original loom.
It is therefore overkill in my estimation but the same as the wire i used previously when doing the original alterations to the starter relay mod and 'hard wiring' the Dyna 'S' mods.

The total load on the positive side of the battery (cables) for distribution at the fuse board i cant help with but likely no larger than the original would be necessary.

Not sure if this helps or not.

AL

[Royalratch]

Thanks again.

I'm using compleyelt new components from Reg / Rect, Generator and Starter Relay etc etc.

Wiring between Dyna-Coils / Dyna-S and spark plugs looks straightforward enough too...