Lotus Elan

Wiring redesign - a good idea?

PostPost by: gerrym » Mon Apr 18, 2011 4:19 pm

Andy, go for it.

The original wiring design can be improved in numerous ways. Statistically the number of Elans that have been damaged / written off by wiring electrical faults warrants the changes IMHO.

The key is to document what you are doing. (Ie produce circuit diagrams for lighting, ignition, charging, instrument panels, etc). That way it can be manageable to produce rather than trying to squeeze it on one sheet of paper. Stick to black for earths. Keep the heavy current out of the dashboard.... Understand how to make relays work reliably...

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PostPost by: Robbie693 » Mon Apr 18, 2011 5:11 pm

Hi Frank,

Only the Plus 2 'S' had the 4 fuse box/relay arrangement - when the S130 was introduced Lotus, in their wisdom, deleted this and went to just four fuses in the dash and no relays at all!

No idea why.


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PostPost by: GrUmPyBoDgEr » Mon Apr 18, 2011 6:19 pm

Higs wrote:For what it is worth, I decided that if I was going to spend significant money of restoring my Plus 2, then I would not want to lose it as a result of an electrical fire! Plenty of Elans have finished this way. So I have gone for broke and fitted fuses to most circuits, relays to headlights, windows etc..

In this way, individual failures of one circuit (whether this is because of wiring, component, switch or connector failure) will not effect the rest of the car and old, hard to get things like switches are protected by using relays to reduce the current through them.

To make me feel better, I unwrapped all the old looms and saw the condition of the old wiring (!).

All my fuses and relays are behind a panel in the glovebox (the usable volume of the glovebox is therefore reduced) so are easy to get at / change.

All of this is written up in various spreadsheets and documents for future owners.

One thing I also did was to replace the wire from the solenoid to the dashboard / alternator. This was woefully underspecced and I replace it with a wire capable of taking 70 amps+.

In summary, my view is that a burnt out elan has very little future value so do the sensible thing and protect it.

Hope this helps.


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down to earth common sense from a fellow West Countryman :lol: :lol: :lol:
This is a case of forget the originality; keep it running & keep it safe :wink:
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PostPost by: Spyder fan » Mon Apr 18, 2011 6:51 pm

Consider using an off the shelf wiring loom http://www.premierwiring.co.uk/our-products/wiring-looms my +2 has a Uniloom and it is standard fitement for all Spyder factory conversions. No relays, no mess of wires under the bonnet and absolutely no problems. A simple fuse box sits in the glove compartment (see picture).

glovebox-drop-down-flap.jpg and

I have heated front and rear screens, Bi Xenon Headlamps, central locking and all the original door puddle lamps, ashtray lights etc etc all work perfectly all the time.

Just keep a wiring diagram and notes on specific fitment with the car, surely not even the most hardened and bigoted purist could object to that.

Kindest regards

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PostPost by: CBUEB1771 » Mon Apr 18, 2011 7:31 pm

Frank Howard wrote:So at the same time Lotus was producing Elans with 2 fuses, they were producing +2s with 16 fuses? Do other +2 owners have 4 of the four-fuse Lucas fuse boxes as standard fitment as well?

Oops, I meant to say three, four-fuse units for a total of twelve fuses in the federal +2S.
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PostPost by: Frank Howard » Mon Apr 18, 2011 7:45 pm


Well it's still interesting that at the same time they were building Elans with 2 fuses, they were building +2s with 12.
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PostPost by: rdssdi » Mon Apr 18, 2011 9:36 pm

When I restored my Elan +2 I decided to add and alternator, relays and fuses. I sent the original harness with detailed instructions to Autosparks in the UK. It was expensive but when it was time to install the harness all fit as the original and worked well.

If you look closely you can see the two fuse holders (5 or 6 each) located adjacent to the pedal box.

The largest single reason for loss of collector cars is fire. Probably many of those electrical related. In addition to the mods that have been discussed, I added a power shut off at the battery. A great idea almost mandatory but difficult in practice. My shut off is located in the trunk (boot) and therefore I have to open the trunk each time I wish to shut off the power.

I have found a convenient way to do this. I will be installing a large amperage latching relay on my TVR. The only wire that is "hot" when the battery is off is a fused lead that triggers the relay. A small hidden spring loaded switch is all that is required. Power is only used when latching and unlatching nthe relay otherwise it draws no current.

underhood.jpg and
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PostPost by: stugilmour » Tue Apr 19, 2011 1:52 am

Wow, lots of ideas and different approaches! Mark me down as voting for a complete modern wiring transformation. Would change any non-standard colours at the same time; don't know for the Sprint but the Plus 2 wiper motor colours are an example. Didn't get a Autosparks or whatever loom as with all the different models of Plus 2 I was pretty sure I would get the wrong one! Pretty much agree with all the mod fans above. A few details I found...

I went with the Lucas Uni-Loom like Alan, which I also purchased from Spyder. Really like it. The loom was easy to understand and modify behind the dash; held together with twist ties rather than loom tape. One could wrap in loom tape if desired when finished. Runs to the corners of the car are contained in modern plastic tubing, which looks great. It is made out of modern thin wall wire to the correct standard colours, so trouble shooting is very easy.

I added relays to a bunch of functions and extra fuses, and located the lot in the glove box as well. The turn signal / hazard flasher circuit requires extensive modification and some extra relays to work with the simple stock Lotus switch, which was all a bit of a puzzle but now done and well documented. Added wires for courtesy lights, window lifts, electric pod motors, driving lights, stereo, etc. using correct standard wire colours.

Added modern plastic connectors so dash removal is easy electrically and there are only a few bullets still in the car. Will be adding dielectric grease shortly. Love the modern connectors as they only connect one way, unlike the bullets. Original wiring was all faded, so matching colours at bullet connectors was hard; not an issue now. If going this route, get a high quality crimping tool and the tools for inserting and removing the spade connectors from the connector bodies.

As I did it all myself, trouble shooting and fixing the inevitable errors has been easy. Just working up the final diagrams now; agree with Gerry's approach and making separate diagrams for each circuit set. Probably ten or so 11 x 17 diagrams for the whole car complete with fuse lists, relay lists, etc.

Have no real idea how this mod will effect re-sale, but don't care. Can't really seeing a buyer being put off if the documentation is all there. 8)
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PostPost by: Andy8421 » Wed Apr 20, 2011 5:34 am

Thanks everyone for the replies.

Although I had pretty much decided to go with the redesign approach, I am now convinced. I will try to post some details / pictures as I go on.

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PostPost by: alexblack13 » Wed Apr 20, 2011 7:13 am

Well done on a good decision Andy. It's your car and you should not be at all influenced by what others think. Good advice apart. (well done Tim!) I for one would find this rewire as a big positive if I were ever looking to purchase your car. Sounds like you will get it dead on.

As I said previously I removed all the bullet connections and soldered them before heat shrink sealing each one. Loom tape exactly as Auto sparks used finished the job. It now looks like a continuous loom. Downside is ever having to remove a component. Side light for E.G. But I'm not planning to do so.... :wink: Carefully maintained bullets do work though. I just hate them. Especially those ones normally found just lying there in the nose of the car.

Well done again.. Keep us posted with progress pics etc...

Alex B..... 8)
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