Wire size

[Chris A]

I've just got back indoors after venturing behind the dash on my 13/60. 'The Land That Health & Safety and Good Working Practices Forgot'. Definitely a case of out of sight out of mind. The reason I was there is that,as I briefly mentioned on another thread (Hot weather?), on Monday the petrol & temp gauges dropped to zero for a short while before returning to normal then did it again and stayed there. The heater fan also didn't work. When I started to investigate I noticed that the oil pressure light didn't come on as well, however ign light did.

I thought the most likely causes for all that were a bad connection between ignition switch and voltage stabiliser. When I unscrewed the ignition switch and popped it below the dash to look at it, lets say I got a bit of a surprise. At some point in the past, long past I would say, there was a severe short. A couple of the white wires that feed the gauges and oil light are well and truly fried! After making sure they were clear of any metal structure I turned the ignition on and low and behold there was light and the petrol gauge started to move, with a bit more jiggling the fan even started up - although after a couple of on/offs it refused. Temporary 'repair' carried out but of course I do need to replace the 2 sections of wire, so at long last the point of this posting:

What size is the white wire that runs from the ignition switch to gauges & voltage stabiliser, please?

It feels a bit thicker than any of the wires (3) I have in stock plus I don't have white.

I also seem to have my full quota of Scotch locks under there as well so I'll have to resort to bullet or spade connectors instead.

When I replace the burnt stuff I'll do another search for the cause of the fan problem. I'll need to remove the radio to give more 'elbow' room.

Coffee time!

[NonMember]

The white wire to the coil needs to be substantial but the other circuits less so. The voltage stabiliser and gauges only needs 1A wire but that's way too thin to crimp into a lucar terminal. If it's powering other circuits too then you need fatter - brake lights are about 4A, wiper motor similar, fan motor a little less. The smallest wire gauge sold by most of the vehicle wiring products people is rated for 8.5A

[RogerH]

A typical  small current 'thin walled' wire runs at about 11amps.

Cables

To be safe only put half the current through it    So an 11amp (16/.020) would be happy with 5amps

Your ignition White wires would be happy with this.

 

Roger

[Chris A]

Thanks for the replies. From what you say 0.5mm² would do, but that isn't as thick as what is there, unless of course the old wire has a much thicker insulation layer - that is very likely.

Think I'll go for either a thin wall of 0.75mm² or 1.0mm² -the prices are hardly different and I only need a metre or 2 max.

My usual supplier also does a thick wall at 0.65mm² (5.75a max) or 1.00mm² (8.75A max) both the same price.

I'll see if the local car spares place does wire as well - the postal costs would be more than the cost of the wire and I don't need any other electrical bits (stocked up with my last order).

[NonMember]

Automotive wire is generally thick wall and derated from the figures used on equipment wire. This is because thinwall wire rated at 11A is only so rated in a 25C ambient and in-car is likely much hotter. Also, thinwall is generally not very resistant to vibration.

A car spares place is likely to have only a very limited selection - probably reels of 17A or 35A rated wire in brown, blue or black only.

[Wagger]

OK I do my own thing, but I have loads of 3 core flexible mains cable, 10 to 16 amp and in Black, Brown, Grey and White. I know that is not 'Original' but it gives me 12 wires that I can identify without labels AND they are double insulated. I've not used these on the Vitesse (YET), but do so regularly on 'Moderns' to replace fractured looms in tailgate wiring.

I once made a 150 way loom for an Automatic test station using all colours with a different colour sleeves on each bunch of ten before reverting to labels.

Before then I worked for a company that only used one colour and cable markers that were sleeves.

[Chris A]

1 hour ago, NonMember said:

A car spares place is likely to have only a very limited selection - probably reels of 17A or 35A rated wire in brown, blue or black only.

Not even that good, in 1.00mm² they only had red or black and sold it only by the 'bobine' (reel)

I am going to compromise and use some 1.00mm² white with brown trace I have in stock, close enough to original. Anyway it won't be seen as it will be with all the other stuff behind the dashboard 😁