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Garage / Re: It's not easy being green - 1971 TC
« Last post by EuropaTC on Today at 10:35:56 PM »That's something I've wondered about.
I don't know the gauge or amps rating of the 'big' brown wire, but is it much different to normal cars running a 70 amp alternator?
At a glance, it doesn't seem so but I'm no expert.
Enquiring minds and all that...
When I fitted the A127 it comes in several ratings (55/65/70/?? IIRC), the higher ones don't use the spade terminal plug but are stud connections with, from the photos I saw, fairly chunky wiring. There are plenty of cable guides on the internet but most of them stopped at 50amps. I did find one supplier that gave a 70amp rating and that was massive, almost 8mm and I don't think I've ever seen that in a car before.
https://www.autoelectricsupplies.co.uk/p/standard-cable
To be honest it's mostly above my head. I could never grasp electronics, if I can't see it, touch it or hit it, then it's black magic. After reading about wire lengths/diameters/voltage drops I guessed the big problems were voltage drops or the wire getting overheated. With the ammeter in the dash and what's probably a longer cable run than most cars I figured Lotus had probably sized their cable on a 30amp rating (5mm on that chart). But as I'd never seen anywhere near 30amps before I just put the A127 in and watched the ammeter. It works and after running for what's now several years (2016) there's no visible problems on the brown wires, so technically correct or not, it seems to work ok.