electrical nightmare

[Etienne B.]

Evening chaps,
Quite a long time I haven't contributed to Mark's forum, but I wasn't totally inactive !
well, this happened this previous week-end, but probably should have happened before ...
With a friend of mine, we were trying hard for our first ever regularity rally - at night, to be it noted.
My car was hardly ready in time to check in at 7PM, take the road-book, and ... go !
But not for long ! After less than an hour, among some "turn right 100 m" or other "left now - too late mate !" my attention was captivated by a very quiet if not positive notice by my navigator : "something is burning in your dashboard Etienne", this assessment being supported by quite a splendid white smoke and relevant and evocative smell of burnt wires. Ah !
I just switched off the lights with a few minutes before total darkness to take advantage of, only to stop at the following CP. But I didn't find anything wrong then, except that the switch of the lights was hotter than normal ...
At the main CP, I was told that my pride didn't show any lights at the back. Mmmmh - with a few minutes in hands - normally to have a quick meal - I decided to be a bit more serious and investigate what happened - SHOCK HORROR !
The wire for the back lights was burnt right behind the switch, for more that the 10 or so inches - actually I couldn't cut the main coton wrap any longer to see the condition of the wire in the main loom - and same for the trip for the number plate light at the back - burnt right down to the main loom, with exposed copper wire just next to the LH tank - perfect. This disaster soon to happen was only avoided thanks to the wire being cut just next to the switch - or was this the main reason, I don't know.
I then spent very long minutes to re-wire the back light - minus the number plate one - with what I had at hand, mainly borrowed unadapted material - just to restart before being off time - and we finished 8th among 31 classified crews - not too bad for a first ever event even if modest.
Back home now, with a few days to think about it, I think that I must resign myself to rebuilt a serious loom - hardly an easy choice when you try to keep as much original components of your car as possible - THIS SOUNDS JUST STUPID NOW, I know ...
My opinion is that, given the condition of the copper, and generally speaking the remaining of the loom around it, it really was cooked by a strong short cut. The white smoke was produced by burning isolating tape. I then guess that the cotton insulating material of some other trips might well be irremediably deteriorated, don't you think so ?
Trouble is rebuilding the loom myself is very tempting, except that I am not unemployed nor divorced yet - well either that or I am unaware of something important - and the existing loom has been modified in the past for adapting the car to its rallying career, so it may not be the best master to copy.
Adapting a readily available one looks the best option, but :
- are any of those looms good quality ?
- Is there one adapted to a 1964 Cooper S originally shipped to France - that is with separate side lamps in the indicator units ?
- what is the difference between a loom built for a dynamo and one built for an alternator : shouldn't the late one have an extra trip ? Or is it only a matter of length of wires ?
- should really the cotton braid be blue traced ? I must say that mine being old is just light grey and possibly yellowishly traced, but nothing sure there unless I check parts hidden under the top rail,
- do you usually add extra fuses or rewire the main lights or other demanding equipments through a relay ?
Generally speaking, any advice would be much appreciated, as you have probably understand, I am quite an irresponsible and totally unqualified "enthusiast".
Cheers,
Etienne

[mk1]

Hi Etienne,

I am really sorry to hear about your recent problems. I am sure you are disappointed that this happened, but on the good side I know of many people who have lost cars when a short circuit like that has got hold.

In my experience you will be better off calling this wiring loom scrap, removing it & starting again. The risk of the short having done even more damage deep inside the loom is very high indeed. Have you managed to work out what actually caused the short, there must have been some underlying problem that started it.

I can conform that the looms that are supplied by Auto sparks are very good quality indeed & they will also make a loom to order with any extra or special connections that you may need.

However, if you are happy to do a bit of adapting of a loom, I have a suggestion.

I have recently removed an almost new loom from my Speedwell car its a standard autosparks loom for a 1965 Cooper S. I am having a special loom made using the correct blue trace colour so this one is surplus to my requirements, I am happy to post it to you for free if you pay for the postage costs. As I say it will I am sure, need some modifications, but if you think you are up to the job it will certainly save you a few pounds.

I hope you manage to get things sorted out soon & well done for your result, in view of your problems you did very well!

[Etienne B.]

Hello Mark,

Thank you for your help and proposal, I feel much grateful, as for this very helpful and friendly forum you initiated and keep alive, thank you again.
I'll send you a mail, and owe you a few good beers if I can come with the S to Beaulieu as planned !!

I am now convinced that I have to rebuild a new loom, I indeed agree that the damage should extend to others wires, not to mention other trouble to happen if I keep using this one ... Enguerrand - aka Pluto here - told me no longer than yesterday that a fellow french Mini enthusiast recently lost his mkII S in a fire caused by a short.

I would still like to add protection to the loom :
- which fuse box would you recommend if not using a modern one ? I though I could fix it under the lower dashboard "shelve",
- or would you alternatively use in-line fuses ? I have bad memories of my Spi original in-line fuses, that I swapped for modern boxes, but I may find a better part,
- which relay box would you recommend for wiring the main front lamps, and, independently, two extra driving lamps ?

Thanks again,
Etienne