Still wired-Still Tired! And feeling Disconnected...

[mjbeanie]

HI everyone,

I have been reviewing my dash harness installation that I've been trying to sort for about forever. (first post "Wired and Tired" circa Aug. 21) This is part d'eux. My car is a 71 Lotus Elan Plus 2S130 "early", Big valve, 3 fuse box, alternator based, Federal Model. It is as built, no mods except a paint job prior to my ownership. Oops I forgot one item, Serial number 0179N built Aug 71.

Given that excessive intro I was hopeful when I bought my harness from British Wiring they would send me a harness similar to the car on-hand. (Puchased Harness p.n's 1868, 1870 and 869 for the dash, main and body harness respectively). I was assured by the website as well as on-site personnel, that I would be "good to go".
Its not good, and I'm going nowhere. Many issues... "Houston"- get a fresh pencil...

The old wiring followed the drawing specs as outlined in the shop manual perfectly well.
However, the harness received does not track with the print. Particularly in the areas of the hazard switch, DB10 Relay box, directional switch. I have been studying this for hours and days, trying to make sense of what is wrong with the as-received harness. The indicator and hazard relay sockets and connections came hard wired from British wiring. I followed this wiring and it did not match with my wiring diagram, it finally became clear what happened.

Contrary to the website description, British wiring used the Plus 2S non-federal Spec when they built the harness! Unfortunately this is not a simple simple fix in my view.

I could possibly follow the loom and use already in place non-federal spec wires. But this has a trickle down affect on other components.(hazard switch differences, directional switch connectons etc) The non-federal spec for one thing, has no DB10 Relay box. So.. If I use LGN Light green/brown wire from the indicator flasher unit to the indicator switch, according to the non-federal spec, I won't have anything to go to pin 1 of the DB10. I also don't know if I should add a wire or not connect one to the DB10. My car has a 5 lug hazard switch with different wires connecting it. The BW non-federal harness uses a 6 lug switch and again wires and color codes don't line up with the Federal spec. The functionality of the circuit has changed significantly. I am actually very frustrated given all the hours involved sorting this vendor's product. I have written to them as well.

(I was considering switching to and Autospark harness but I don't know if Autospark makes their own harnesses or buys them from British wiring, -the vendor part numbers used are identical. )

Thanks very much for your suggestions. Photo Extracts below.

Federal version (my Plus 2), should be the first photo (with DB10)
The harness was built to the second photo it seems.

Thanks for your comments and suggestions..it is appreciated. Time for a cold beer, but I guess that depends on who wired up the fridge..
Cheers,
Mike

[GLB]

I think British wiring buys their harness from Auto Sparks but I may be wrong. I have used Auto Sparks in my Elan 1600, easy to do and also in my federal +2s, ( 12 fuse and 4 relays). the behind the dash area was difficult but only because of the lack of room. I had to reuse the original terminal connectors between the front and main looms because I was told they were NLA, but it all worked out. Gary

[alanr]

Autosparks manufacturer their own wiring looms for a large number of British classic cars. They are made in house and sell them all over world. They don't buy any in. I have personally watched them being made.

Alan

[mjbeanie]

Hello,

I just heard back from Autosparks. They do indeed supply harnesses (made in house) to British Wiring.
So whatever source you use, you're buying an Autosparks-manufactured harness.

[Craven]

How much help if any this will be, as you say “Contrary to the website description, British wiring used the Plus 2S non-federal Spec when they built the harness! Unfortunately this is not a simple simple fix in my view.”
The circuit arrangement is the result of some clever thinking! To use the Brake stop light bulb for both brake and turn signals, OK to use in states where both are Red in colour. Simple surely!!!!
https://www.gglotus.org/ggtech/relaybox/body-relay.htm

[mjbeanie]

Thanks for the response.

But there's plenty to fix, and troubleshoot on the car already, without having to recover vendor missteps. At least 6 other components (hazard relay, indicator relay, indicator switch, relay box, center fuse box, and hazard switch) are affected. All require sorting and rewiring to the spec that should have been manufactured by the vendor.

This is not well-received, particularly after spending $325.00 for this "new" harness, that was confirmed for the Lotus Plus 2S FEDERAL Specification.

The "best" replacement parts are the ones that are "plug and play" and do not require troubleshooting upon receipt.
(The received components fit and function as intended, right out of the box.)

However I thank you kindly, for the detailed description on the relay box functionality. I am in contact with the vendor regarding this issue and will advise anything noteworthy. Apologies for sounding frustrated as well. Cheers, Mike

[stugilmour]

Mike, not sure if I mentioned directly to you in our PM’s that I used a replacement loom from Spyder that completely departs from stock. It uses modern practice with only one flasher relay for both the indicator and emergency flasher circuits. Makes it more difficult for me to provide specific useful advise to get around your loom compatibility.

Sounding like ditching the DB10 box all together and using the new loom configuration might be the best way forward. I haven’t looked in detail at the diagrams yet, but surely your new loom has the required runs to the four corners of the car, so any required modification can be limited to behind the dash and only requires unwrapping minimal lengths of the dash loom?

I do recall adapting my loom to the Federal switches was a bit of a puzzle. I ended up using three additional Bosch style relays (one double make and break and two changeover) to reliably provide the required switching, only using two terminals on the stock emergency flasher dash switch to trigger the relays as required to make it all work. As my modern flasher relay doesn’t have a ‘pilot’ terminal (used to isolate the single filament dash turn signal indicator) I had to use a couple of inline diodes to make it all work.

Not trying to confuse the issue as obviously my situation is completely different, but perhaps some diodes and relays can be craftily added to modify your dash switch terminal functions. Going to first principles the following might help

- The emergency flasher relay has to be supplied from Purple - Hot at all times, fused (or equivalent).
- The turn signal flasher has to be supplied from Green - Hot in run & start, fused (or equivalent).
- When the emergency flasher is on the two sides of the car need to be connected. I used the double make and break relay to do this, and it works great.
- The dash pilot lamp can, if required, be isolated with diodes. These ones work well as they are robust enough and use conventional spade connectors

https://www.autoelectricsupplies.co.uk/product/748

- My turn signal dash pilot lamp flashes with the emergency flashers. Not a big deal but not sure if the stock configuration works this way.
- My turn signal dash pilot lamp is grounded in the dash; the left and right indicator wires with diodes supply the filament while preventing connection of the two sides together. IIRC this is different from stock.
- The warning lamp above the emergency flasher switch flashes when on. Thinking it over now, might have been better to configure things so it stays on steady? Can someone describe how it works in the stock setup? Probably not a big deal to put either way.

Perhaps I can take a look at the two highlighted diagrams that best reflect what your car started as and what your loom has available. Started snowing here again so won’t be able to look for a while though. From your posted pictures I can see the two diagrams in my WSM.

Just a thought. Totally get the frustration. Unfortunately I do not recall another forum member posting a clearly outlined modification that will solve your specific issue, although I am pretty sure others have been through the process. Perhaps we can figure something out that is pretty simple to add behind the dash and eliminate the DB10 at the same time.

Questions.

Where was the DB10 located in the car? Never dealt with one, just read a bunch of posts.

Are the loom runs behind the dash largely loose or are they wrapped with loom tape? If wrapped and needing disassembly, use non-adhesive stuff to re-wrap rather than adhesive electrical tape, which just makes a mess.

https://www.autoelectricsupplies.co.uk/product/348

Cheers. HTH.

Stu

PS. Whatever you come up with, carefully document for future troubleshooting as it will be unique. I did this reasonably well, but forgot to take some detailed photos so I knew the physical location of everything. Ended up having to take the dash out to change a flasher relay because I did not recall where I had placed it with all the loom modifications. Turned out all I had to do was remove the ash tray to gain access, but I didn’t recall this detail.

[Craven]

If it’s your future idea to do away with the DB 10 arrangement and use non-federal, then if my interpretation of this relay function is correct, be careful as your car will not have dual wiring to the rear of car for separate brake and indicators plus your tail light units themselves may not accommodate dual filament bulbs, you will do well to check out this first.
FWIW

[stugilmour]

If it’s your future idea to do away with the DB 10 arrangement and use non-federal, then if my interpretation of this relay function is correct, be careful as your car will not have dual wiring to the rear of car for separate brake and indicators plus your tail light units themselves may not accommodate dual filament bulbs, you will do well to check out this first.
FWIW

Excellent points. Assuming the replacement loom will have the wire runs, but man those tail lamp and front sidelight housings are spendy if you need them. I replaced my rear housings at the time, and the available ones did accommodate the dual filament bulbs. Will be interesting to see what Mike finds with his. Although not ideal, it may be possible to change the bulb sockets to dual filaments.

Cheers. HTH

Stu

[mjbeanie]

Thanks for the excellent and detailed feedback. As a retired engineer from the jet engine world (at Pratt and Whitney), I really appreciate the insight and technical expertise of this community! I owe you all a beer!

I am in the hands of Autosparks engineering department. Detailed drawings of both the Non-Federal and Federal cars have been provided to them. I'm standing by. My first choice remains to keep this car as built as a Federal car, as it is registered with Andy Graham at Lotus HQ and I don't wish to alter the original build.
(Thought I would post the the full drawings here as well for those folks who might find it interesting.) Hopefully it is clear enough to read. Apologies for the glare. Will advise any feedback once received.

Also don't know why these photos may load upside down to this post. At a minimum I would have thought the Federal Print would be upside down, and the Non-Federal, right side up (or vice versa...)

[GLB]

I should have mentioned in my previous post that the wiring loom I got for Autosparks was configured for the DB 10 relay box in my federal +2s so they do supply them. Sounds like you just got the wrong one from British wiring. Maybe mislabeled? Gary

[stugilmour]

Excellent Mike. Can you confirm if your rear light housings accommodate dual filament bulbs and the stock location of the DB10? Basically just curious.

[The Veg]

If it's any consolation, I have a '70 Federal that seems to be an early car from the transitional period when the S began to supersede the non-S +2, and I have yet to find a wiring diagram that exactly matches what's in my car. The one that's closest in most regards I took to a copy-shop and had them blow it up to 2' x 3' and it permanently resides on the wall in the garage.

[mjbeanie]

Gary,

Thanks for that feedback, I am encouraged there are such harnesses available for this specification. While I have invested way too many hours installing this one, I would be thrilled to get the right one.

Stu thanks again for all you help and suggestions. The Lucas,DB10 Relay box sits on the firewall, left of the steering wheel, above the emergency brake handle. Will advise further on the brake lights.
Some photos are attached.

[gjz30075]

I took to a copy-shop and had them blow it up to 2' x 3' and it permanently resides on the wall in the garage.

I did the same with several. And laminate them.