Wiring Looms - Rewiring 0037N (1970 Federal +2S)

[Andy8421]

As anyone who has waded through my posts will know, I have a pretty low opinion of the wiring on the Elan. I have never seen anyone credited (or blamed) for the design, and the pictures of your engine bay reminded me of one of the more bizarre aspects of the wiring design.

My S3 and Sprint have the grand total of 2 fuses each, your +2 (if I have found the correct diagram) has 12. My own opinion is 12 is closer to the right number, but I have never established what caused the change of heart at Lotus.

Does anyone know the reason?

Andy.

[nwbaxter66]

Andy
Without any knowledge, the fact that in 1969 there were a minimal number and in 1970, there were 12 plus four relays and then the number stabilized suggests there was either a regulation or an individual as the root cause. I was looking with jealousy at the other re-looming project going on in the UK on a 69 !
I too would be interested in the actual root cause for this complexity that will be and has been causing me fits.
N

[stugilmour]

Any good suggestions on a circuit tester/tracer, apply power one end, see when bulb lights up the other - should probably just make one, but interested if there are recommendations for the US based?
thanks
N

Nick, a suggestion I liked when I did my rewiring job was to insert a low amperage inline fuse to the main positive lead to the new loom (essentially between the battery positive and the main brown that powers everything). The idea is should you accidentally short a circuit anywhere in the loom while assembling & testing, the main fuse should protect everything. Any good quality test lamp or multimeter can be used to check each circuit as you go.

You mentioned making some running changes, perhaps relays, additional fusing etc. I found it easier to assemble the entire loom outside the car with everything emanating from the new dash. Did it on the carpeted family room floor as a warm winter project.

Once I had everything working I loosely fitted the dash to the car. I used modern connectors for everything, but this may not appeal to you. One think to consider, even if you retain a lot of the bullet connectors at the various devises, is to have modern multi connectors for each leg of the engine bay runs, the rear loom run, and the various minor connections to the courtesy lights, window lifts, etc. The idea is to have several easily disconnected multi connectors that allow the dash to be fitted and removed easily rather than twenty or thirty separate bullets that have to be assembled under the dash.

I also used several main ground runs within each loom leg. I located a main ground bus at the right hand side dash mounting bolt. When adding a relay, I used smaller gauge thin wall cable in the same colour scheme for the relay trigger and the supplied larger gauge cable for the load from the fuse box. As I was adding several relays, I opted to mount the new fuse box and relays in the glove box so the whole affair cones out with the dash. You may wish to do it differently, but suggest sketching up your loom layout before you start.

If you do opt for circuit modifications, make sure you document the changes. Rather than trying to make a modified circuit diagram, I used 11 x17 card stock to sketch out each circuit separately using coloured felt markers. Sounds like a bunch of work, but not really a big deal while you are at it (and you can see and remember everything).

One thing to consider adding is some additional accessory circuits. I installed a couple of cigarette lighter receptacles under the dash for modern electronics like a Garmin, the phone, etc. Prewired USB receptacles would probably work better now.

Although this was all on my Plus 2 I would probably do it in a similar fashion for an Elan.

HTH. Make sure you ask any detailed questions as you go; suggest noting your model and build year in the question. All the best. I found rewiring a great project to take on myself as it really just requires patience and persistence, Added bonus is you will fully understand the wiring system when you are done.

Cheers

Stu

[1owner69Elan]

As an original owner of an S4 I always thought the wiring design was quite poor. Only 2 fuses and messy looking. When rewiring my car recently I found melted insulation under the dash. I never had a fire but did have the voltage regulator stick once necessitating me hacking the wires off before going completely up in smoke.

I started with new looms from Paul Matty (AutoSparks) and reconfigured them to use additional fuses and relays. The fuses are consolidated inside a small waterproof RTMR (as in the link below) and the wiring throughout is now neat and tidy. Strict adherence to color coding throughout so the next person won't be cursing me when I'm gone.

Also, placed a cutoff switch on the backboard. I always turn this off while the car is parked for peace of mind. Also easily reached in case of an emergency.

Documented here: viewtopic.php?f=38&t=45742&p=327156&hilit=+rtmr#p327156

[nwbaxter66]

thanks for the great advice and suggestions.
The layout and pre install sounds like the way to go, it will allow so much flexibility and the ability to test everything (well almost).
The idea of a new fuse box to replace the three g4 glass fuse box is also to be looked in to.
thanks again

[nwbaxter66]

Dreaming on a Saturday Morning.

its been so long since I acquired the new dash, it could almost be considered antique! Walnut Burlwood veneer from Randy Keller at Prestige Autowood in CA. The pictures don't really do it justice.
Had to pull the voltmeter when the one in the car went bad!
Seats out.

[Matt Elan]

Hi nick
Comparing notes is good!
Today I got the rear half of my rear loom out and spent some time sorting out some random extra features - boot lights and some weird earths. Then sat down with the new rear loom to work out what went where. I’ve got a full set of wires for one rear cluster rear marker, brake, reversing and indicator and earth but only the reversing light, indicator and brake light on the other...... so it’s well worth taking your time and checking the new loom so you can see if you’ll need to run any extra wires for the new loom!

[nwbaxter66]

First snag ...
I have got the dash moving, but it would appear that one has to allow the steering column to move down - there seem to be a couple of bolts securing a u bolt to a bracket - then there is a second ubolt that bolts through to the engine bay.
Do you release both of them ?
thanks

[HCA]

Bear in mind that as soon as you loosen the u bolts, the column will put unnecessary strain on the steering pinion...

I would fist loosen the u bolts holding the steering rack to the chassis, take out the retaining bolt of the pinion (helpful if you do this with the steering wheel in the dead ahead position), detach the seal where the column enters the body, then remove the u bolts holding the column to the body, and withdraw the whole thing. (of course detaching all the wires to the ign switch and stalk beforehand...)

This gives you more room to work in.

[mbell]

You need to remove the nuts on both clamps to drop/remove the column.

The strain is a good point but only applies if you have the standard coupling. If you have a u joint type there shouldn't be an issue.

[nwbaxter66]

Thanks much
Old loom out, Matt's 69 loom looking very attractive right now...

[HCA]

You need to remove the nuts on both clamps to drop/remove the column.

The strain is a good point but only applies if you have the standard coupling. If you have a u joint type there shouldn't be an issue.

Apologies! Yes, I forgot about the UJ there. Just disconnect here and forget about the rack! I must have subconciously been harking back to my mini days...

[nwbaxter66]

Lesson learned - while I love the guys at Project Binky and Bad Obsession Motorsport, the mechanical ability in their big toes exceeds my total knowledge, so when wearing the appropriate swag, it does tend to tempt fate a little!

What started out as a "well let's just run the sander to smooth out that unsightly bit of 'glass on the driver's side engine bay" to an "ok, there's the rest of the damage from when the DPO put the jack through the floor of the bodyshell many years in the past" moment.

Monday evening will be f'glassing evening - at least the temperature means no additional heat needed and I know I can do a better job than the last guy !!!

And I will drop the pedal box off to the powder coaters...

[Bigbaldybloke]

My two penny worth would be take lots of photos, get new bulkhead grommets, if making any changes invest in a selection of really good quality crimping tools and buy good quality crimps. Probably too late now but if possible use the right angled blade connectors onto the instruments and switches behind the dash, gives a better finish and more room. Also if modifying the wiring buy a selection of correctly coloured wire and if extending wires inside a harness, solder the joint then cover with adhesive filled heat shrink, it seals better than ordinary heat shrink. Finally if you do modify the harnesses and add additional fuses make yourself an updated wiring diagram as in a few years time you’ll not remember what is what. Happy wiring!

[Bigbaldybloke]

Just a suggestion, I fitted a usb socket behind the ashtray holder. I can then remove the ashtray and I have a small satnav that attaches to the ashtray surround by bar magnets. The original ashtray just slots back in as normal if you don’t need the satnav. You just have to cut out some of the ashtray holder and yours has a light in it you will have to sacrifice that.