Lotus Seven
Paul looms in on Seven’s electrics resurrection
Like many enthusiasts, my brain hurts when contemplating vehicle wiring, even on a simple machine like a Fifties Lotus. But I am determined to do as much as possible on my Seven myself, not least because I’m a tightwad, so I wasn’t going to farm out the job.
Due to the variations in these hand-built cars there isn’t a standard wiring loom available off the shelf, but I had a secondhand dash panel among the parts I bought from specialist Mike Brotherwood, so my plan was simple: buy all the instruments and switches I needed and a great big pile of different-coloured wire, then attach them all together. How hard could it be?
The first stumbling block was the eye-watering price of some of the correct original parts. Mike had warned me that the AC oil pressure gauge used on the early cars was hard to find, but after two sold for £250 each on ebay and seeing similar prices for unrestored Smiths chronometric speedometers, I decided would have to compromise. I’ve put together a nearperiod looking dash from slightly later – and much cheaper – Sixties AC gauges as well as new reproductions of the Smiths rev counter and speedo (the latter came from India and cost just £4.99 plus £8 postage – fingers crossed…).
As the AC temperature gauge I’m using is an electric one rather than mechanical, I also needed to add a voltage regulator that I found at Demon Tweeks. This is intended for Smiths gauges, but like the sender unit I’m hoping it will work with the AC one I have. I forked out for a new Lucas PLC5 ignition and headlight switch from ebay and also a genuine Lucas SF4 fuse box from Auto Electrical Supplies. Autojumbles proved a good source of lights and switches though, including the distinctive Austin A35 indicator switch. I have placed this where the similar-looking horn-dip switch would have been originally, since Series 1 cars did not have indicators as standard, and the horn-dip switches fall into the ‘rare and expensive’ category. Although I’m sure some purists will tut,
I’m pleased with the way the dash has turned out, even though I was alarmed when I realised that despite my penny-pinching the lights, instruments, charging system and wiring have added up to nearly £900.
Tiring wiring
On any project like this, you should start by drawing up a clear wiring diagram from which to work. But being impatient, I didn’t – I worked from a Lotus Seven Series 2 wiring diagram, an Austin A35 owners manual, and my own imagination. After several days of painstakingly routing wire around the car and temporarily taping it in place, I began to get close to a finished loom. I saved having to buy many rolls of cable as Towzatronics sell five-metre lengths of the colours I needed via its ebay shop, as well as the brass connectors and crimping tools. I also saved a few pounds as another workshop dweller donated some relays for the headlights.
The headlights are not period-correct, because Lotus didn’t fit any, just two differently-angled spotlamps – one for main, one for dip – to meet the bare minimum of the Fifties’ lax lighting requirements. Having carefully considered which I felt more important – restoration accuracy or not crashing into things at night – I plumped for five-inch units from Car Builder Solutions that also contain sidelights, which allow me to repurpose the sidelights as indicators by using amber bulbs. As a bonus they have main beam warning lights on the top, which saves a little bit of dash wiring.
Due to the age of the car, it’s legal to have red indicators at the rear, which could have been contained within the rare, original-spec Wingard lights (£58 secondhand, another ebay find) but again I’ve opted for safety first in the form of amber Lucas L488 units that won’t look too out of place.
Another unobtrusive modification is the Dynomator from Accuspark, a 45 amp alternator disguised as a dynamo. Available as negative or positive earth (I’m going negative), it also has a drive for the mechanical tacho. A £130 deal at the Stoneleigh MG and Triumph Spares Day, it wasn’t much more than a new dynamo and voltage regulator. I live in London and most of my journeys are in traffic with the engine idling, so it should charge more effectively than the original system while keeping the engine bay looking correct.
Bad earths are often the source of electrical maladies, so I welded studs to the frame where I needed to ensure good earthing points. A Halfords 038 battery listed for a Morris Minor perfectly fitted the tray and its installation allowed me to test most of the system. Then I triumphantly began to wrap it all in cloth insulating tape – until I realised I’d forgotten to run a wire to the temperature sender at the front of the engine, at which point I started unwrapping it again.
Testing also showed that the new light switch had an internal fault, so was sent back for replacement. I am going to hold off taping everything up until I’ve got through the MOT and have made the decision whether I’m having a full windscreen (and hence wipers) or not. But I’m pretty chuffed that I’ve very nearly finished completely wiring my own car. And, before you ask, yes I will be carrying a fire extinguisher.