question What wire sizes to use in 6 volt circuits.

[gritineye]

Somebody please help me! :banghead:

 

I'm trying to buy wire for rewiring my 1928 6 v Chevy and this has been giving me a headache all day , and there must be others who would benefit from knowing what size of wire to use when rewiring a 6 v vehicle.

 

Found plenty of info on converting 6 v to 12 v, and some info on AWG sizes for 6 volt, but nothing simple in the metric wire sizes sold in UK.

 

Just can't get my head around all the watts amps wire gauge metric nonsense..:sweat:

 

Has anyone got a simple easily understood list of metric sizes for a 6 volt loom?

 

Headlights 36 w.

 

Sidelights 5w

 

Stop lights/indicators 21w

 

Dynamo feed wire

 

Battery to ammeter feed wire

 

Here is what I have to replicate with the addition of 2 extra rear stop tail lamps an an indicator circuit.

 

 

Any help would be gratefully received !

[lowfat]

http://www.sengpielaudio.com/calculator-ohm.htm

 

fill in this to get your circuit amps then look at the data you have already to get wire size

 

http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=guide_awg_to_metric

[gritineye]

Thanks lowfat, but I've been at those things all afternoon and matching it all up is way too much for someone as numerically dyslexic as me, yes I really am that bad at it.

 

I do need a just simple list.

[Tony B]

Actaully mate it's called Discalculia with numbers. The other symptom is difficulty remebering faces (That's my excuse!)

[radiomike7]

Thanks lowfat, but I've been at those things all afternoon and matching it all up is way too much for someone as numerically dyslexic as me, yes I really am that bad at it.

 

I do need a just simple list.

 

 

Bernard, up to a point where the insulation breaks down you don't need to consider volts, just the current carrying capability of the cable.

 

For DC, Watts=Voltsxamps so your 36W bulbs draw 36/6=6amps each

5W .............. 5/6=0.8amp

21W ............. 21/6=3.5amps

 

I would strongly suggest using modern thinwall cable, it has a high temperature outer sleeve with a high purity copper multistrand conductor and a 0.75mm is rated at 13amps continuous compared to the old 1mm British cable which was only 8amps. Used at half its capacity for each headlamp you should have an almost unmeasurable volt drop.

 

I use Pole Volt for any specials I am wiring up as they can supply cut lengths in a variety of colours to order. http://www.polevolt.co.uk/acatalog/Thinwall_cable_cut_to_length.html

 

From a mechanical strength point of view I would use a minimum of 0.75mm even on the lower wattage bulbs.

[gritineye]

Thanks Mike, so now I'm thinking the simplest thing to do would be use that .75 for everything and forget all the size stuff, use the same colour for every where and colour code with heat shrink at the terminals.

[gritineye]

Actaully mate it's called Discalculia with numbers. The other symptom is difficulty remebering faces (That's my excuse!)

 

For gooness sake Tony do you know how long it took me to spell duslexia?

[radiomike7]

Thanks Mike, so now I'm thinking the simplest thing to do would be use that .75 for everything and forget all the size stuff, use the same colour for every where and colour code with heat shrink at the terminals.

 

Can do but using different colours for different circuits will make fault finding easier at a later date.

 

You will obviously need thicker gauge cables for the ammeter/charging circuit and the main feed to the light switch; note that twice the cable size does not equate to twice the current capacity.

[lowfat]

http://www.autoelectricsupplies.co.uk/product/978/category/186

 

this is what i use for the run front to back

 

use these codes its standard and will help future owners

 

http://www.autoelectricsupplies.co.uk/cms/files/colour_code_for_vehicle_wiring_-_new_order_2.pdf

[lowfat]

also bear in mind the further something is away from the battery/ dynamo the bigger the wire diameter needs to be to ensure enough power gets to a consumer..

[Pete Ashby]

Somebody please help me! :banghead:

 

I'm trying to buy wire for rewiring my 1928 6 v Chevy and this has been giving me a headache all day , and there must be others who would benefit from knowing what size of wire to use when rewiring a 6 v vehicle.

 

Found plenty of info on converting 6 v to 12 v, and some info on AWG sizes for 6 volt, but nothing simple in the metric wire sizes sold in UK.

 

Just can't get my head around all the watts amps wire gauge metric nonsense..:sweat:

 

Has anyone got a simple easily understood list of metric sizes for a 6 volt loom?

 

Headlights 36 w. 12 gauge

 

Sidelights 5w 14 gauge

 

Stop lights/indicators 21w 14 gauge

 

Dynamo feed wire 12 gauge

 

Battery to ammeter feed wire 12 gauge

 

Here is what I have to replicate with the addition of 2 extra rear stop tail lamps an an indicator circuit. 14 gauge

 

[ATTACH=CONFIG]102544[/ATTACH]

 

Any help would be gratefully received !

 

You can get all the colours you require in the above gauges from Auto Sparks in authentic cotton covered PVC, battery to starter and battery to earth should be 0 or better still 00 gauge

 

Pete

[R Cubed]

If you break the circuits down into their loads ie what bulbs are on that circuit add up their wattages which will give you the total load for that circuit then divide that by the voltage, that will give you the current for that circuit.

 

Then just pick a type of cable which will handle that current.

 

All you need to know is watts divided by volts gives Amps.

 

You can work the other way too by timesing volts by amps to give watts.

[marmon]

http://www.dimebank.com/LucasColours.html

 

This maybe of help, it certainly makes things easier when making up looms and also when checking for faults a few years down the road.

[gritineye]

Thanks for all your relies chaps much appreciated.

 

I've decided to replicate the original wiring harness using braided cable coloured to match the illustration in the manual..

 

Any additional wiring to power safety features like flashers and stop lights will be done in modern wiring.

 

I'm desperately trying to disturb as little as possible on this car but it's not easy to make it mechanically safe to use without spoiling the originality.

 

As the National Trust uses a similar approach this should keep me and some of the rivet counters happy. :-D

 

[Gordon_M]

Nice car. I think the tyres need more attention than the lights though. :blush:

 

You may want to look at getting the headlight lenses replated, not cheap, but will give shiny lights for another seventy years.

 

It is easy to distract from the original appearance by fitting modern indicators and brake lights, no matter how safe they appear. Might be worth investigating 6 volt LED lights which can give a lot of output for a really small light size and they can be much less distracting visually.

 

Ironically if you keep it totally original it should have what we call 'legacy compliance' and be quite legal to run as it came off the production line, but any alterations / additions / improvements have to comply with current rules and regs, of course.

 

If it was mine I'd keep the full original lighting system, and add LED indicators, brake lights, maybe even a high level brake light. Probably some extra reflector capacity on the rear so that modern speeding traffic doesn't get caught out.

[gritineye]

You may want to look at getting the headlight lenses replated, not cheap, but will give shiny lights for another seventy years.

 

It is easy to distract from the original appearance by fitting modern indicators and brake lights, no matter how safe they appear. Might be worth investigating 6 volt LED lights which can give a lot of output for a really small light size and they can be much less distracting visually.

 

Ironically if you keep it totally original it should have what we call 'legacy compliance' and be quite legal to run as it came off the production line, but any alterations / additions / improvements have to comply with current rules and regs, of course.

 

If it was mine I'd keep the full original lighting system, and add LED indicators, brake lights, maybe even a high level brake light. Probably some extra reflector capacity on the rear so that modern speeding traffic doesn't get caught out.

 

Reflectors are fine and rather snazzy I think...

 

 

 

There is only one center rear light fitted originally and I have added modified period repro stop/tail/indicator lights and made some period looking brackets for them.

 

At the front the indicators will be hard to see when not on, and I'll keep the cowl side lights, so I reckon it'll all be quite acceptable.

 

Might look at LEDs, didn't know they where available 6 volt, good suggestion thanks.

[Tony B]

I had the 6 volt LED problem on my WC54 Katy. Decided bugger it as LEDs normally rate at the maximum voltage, ie 12, lets try it anyway. They work fine.