Wiring help needed

[Donnie]

Bought a Series 1 Seven that has always been raced. The only electrics on the car was a tach, stop light and cooling fan. All wired directly to the battery. No generator, no fuses, no head lamps. I ordered a "complete" wiring harness from Autosparks of UK and after 4 months I received it. It got caught up in Covid delays. I got a lot of wire in lovely colors but no wiring diagram. Call them and they told me that no diagram was available. Spent a week trying to make sense of it with very little headway. Studied schematics from other Sevens but nothing matched up. I've  rewired several Brit cars without a hitch but I'm  lost here. Any thoughts out there?

[SENC]

Not S1, but there are a couple S2 wiring diagrams in the download section... may be useful if you can't find an S1 manual or diagram.

[Donnie]

Saw those. Thanks anyway.

[Croc]

 

Not the greatest of service from Autosparks - they should be able to provide you a diagram.  I consider that essential if you buy a wiring harness.  Sorry to hear that you have been getting the run around on this.

 

I assume you bought this

Lotus Seven Wiring Harness Set (autosparks.co.uk)

 

The photo does not look inspiring!  Autosparks does say it is a like for like replacement the but the issue with that is that 1) your car has been modified over time and 2) there was no one wiring harness - things got changed based on parts availability, bright ideas, etc.  

 

If you did modifications, there are technical guides here

Modification Documentation (autosparks.co.uk)

 

But I bet you did not bother with any mods based on your original harness description?

 

You have compared what you have bought from Autosparks to these two diagrams from the technical library section of this site?

 

 

Loom with tacho.pdf

 

 

So at this point my approach, if I were in your shoes, would be to lay out the harness on a big board and then using the color code from the wire color chart guide, try to eliminate the obvious using a tester to trace main and trace feed.   Finding a good specialist auto electrician local to you and presenting this problem to him would also be a viable option - they deal with these types of problems daily.  

British Standard Colour Code | Autosparks

 

[Donnie]

Croc - Actually I did specify (and paid for) two mods. The electric fan mod and the alternator mod. Got the fan mod. Did not get the alternator mod. Lots of extra dangling wires. In addition, the ignition wire grouping and the fuse box grouping are over 3 feet apart. Can't imagine where they proposed I mount the fuse box. Would reach half way

to the front wing.

 I'll study all the info I have and see what I can come up with. Might just trash it and make my own. And to think I complained about devoting 2 days to rewire my Bugeye with a Moss harness. 

 

[Joe Petty]

I had a similar situation with my 1962 S2 Seven, ex-racer with minimal wiring (all in red and black).

 

The good news is that there are very few wires and scant accessories!

 

I searched eBay for a late model MGB harness, stripped it and cleaned all the wires and built my own using the color guide and the above diagram as a guide.

Fortunately, my voltage regulator, fuse box and switches were still in their original places, so I had some idea what the end result should look like.

 

My harness is in 2 parts: underdash + forward and rear lights.  The rear harness connects to the forward harness near the front of the transmission tunnel.

I added fused relays for the headlights since I did not like the idea of all that amperage going through multiple dashboard switches.

 

Since you have done a Bugeye, you will have no problem once you set your mind to this!

 

Good Luck - Joe

 

 

[Donnie]

Thanks all for the info and encouragement.

[SENC]

You might reach out to Mick at xtraspecialsevens.co.uk.  The PO of my S2 Seven had him replace the loom and he did an exceptional and clean job.  He does a lot of Seven work in the UK and may have a diagram.  Very nice and responsive.  Mike Ostrov, of Elite fame, Tony Ingram (lotus7.com), and John Donohoe (simplesevens and also a contributor here) are probably the most knowledgeable stateside and may also have leads or recommendations if you reach out to them.  Keep us posted!

[SanderGA]

If I was in that spot, I’d get a Motogadget M-unit. Watch some videos of it on-line with an open mind and I’m guessing you’ll see it’s a great solution. Several people on this forum have installed them on later cars and that presents more difficulties but on an early model such as yours it should be very easy.

[Donnie]

I have rewired it with my own wire and it's back on the road. Total time, 8 hours. Spent days trying to make sense of the Autosparks harness to no avail. It clearly is not made for my Seven.  Complained to Autosparks twice and got 2 form letters. 

[Vinman1]

I have an AutoSparks harness in mine. Maybe thats why I am having a charging issue?