S4 dash loom: make or buy?

[tonyabacus]

John
Somewhere on the forum is a good photo of an installation in the glove box, very neat and probably worth looking out, I cannot recall exactly where but I think it was headed up something like Fuse Box and Relays. I know that is a pretty general heading but hope it may give some idea of how neat a non standard change can be.
Tony

[JohnCh]

Thanks Tony, but the issue with this specific powerblock is size. It's 7" x 7", whereas the back of the glovebox is only ~4.5" high. Although now that I say that I think there is room to make a custom glovebox that takes advantage of unused space and could accommodate it. I'll need to take some measurements.

[stugilmour]

….Although now that I say that I think there is room to make a custom glovebox that takes advantage of unused space and could accommodate it. I'll need to take some measurements.

Definitely shoot for this. The huge advantage of mounting the power block directly on the dash is a ton of wires kinda stay on the dash as a complete module. The rest of the functional wires coming off the dash & Power Block can all be carefully placed in the car prior to marking them for cutting to add dash block connectors where they will fit in the console/dash side panel area. With a bit of thought a lot of the cutting and crimping could be done out of the car, which makes it a bunch easier. Dash removal is never easy, but at least things can be set up so the wiring doesn’t need a bunch of attention during a future repair job.

Do the pictures on this thread match your glovebox? If so, it looks like there is plenty of room if willing to cut down the depth of the glovebox. What might meet the stock Power Block 7” x 7” dimensions is reducing the height of the glovey with a false bottom to accommodate the relatively modest depth of the Power Block, facing downward or perhaps on a hinge arrangement and facing upward? Might even allow space inside the glovebox at the back to add a secondary relay/fuse box if needed for the windows. Cover the Power Block base in carpet or vinyl and it could be a pretty finished look and still fit a few small items in the glovey. Really nice all the wires off the Power Block come to one side.

viewtopic.php?t=25664&p=167812

Anyway, make sure you allow a ton of room for the wires coming off the block and dash; in the Plus 2 one runs into the eyeball vent ducting at the back of the glovebox and it gets tight. My dash side panels also needed some adjustment.

One thing that helps packaging tremendously is to have two front runs off the dash, left and right. e.g. In the Federal Plus 2 IIRC the right sidelight & headlight, horn, etc run down the driver’s side and across the nose. Way better to bundle the right side stuff together with the wiper motor, ignition, and main +12v bus at the solenoid area because a bunch of wires don’t have to cross the dash, which can get tight particularly if using additional relays for stuff. Unlike Veg, I used several block connectors, grouping for example the wiper run separately sheathed from lighting or ignition. Just a thought.

I have seen threads on the forum where folks have made new a glovebox from scratch and even beautifully flocked the interior. I understand new gloveboxes are available too, but check for your model. I know it improved my confidence when I was cutting mine!

Great news with the compatibility to your existing switch gear. It really looks like a nice piece of kit, and even better if the builder is willing to check things out and maybe add some headlight fusing. Who knows, he may even be able to slightly re-arrange the Power Block to say 5” x 9” or whatever might fit an Elan easily.

Really looking forward to reading how your detailed install goes. Someone has to be first!

[JohnCh]

That looks like the same glovebox. I'll take a closer look at available space later, but I'm pretty sure I can fabricate a replacement that can accommodate the powerblock.

Once I hear back from AAW on a couple of open questions I'll place the order, then will document everything in an upcoming build thread. I suspect I'll have a number of dumb questions for the group before it's back together

[stugilmour]

Fantastic John. Wonderful project, particularly for the winter months.

[stugilmour]

John, finally found the other similar loom kit I mentioned earlier. It is by Classic Technologies….

https://classic-technologies.com/fuse-b ... ifications

Wanted to add it here because it does have a smaller footprint. They call the unit a fuse box, but it appears pretty similar to the Power Block. However, not sure it would necessarily be easier to mount in or around the Elan glove box because the wires attach all around the unit.

It does appear they broadly use the British wire colour standard in their kit, although I only took a quick look.

In any case, their colour PDF wiring diagram on the web site (or the link below) might provide some ideas for your project no matter which vendor you go with.

Cheers

Stu

[JohnCh]

Thanks Stu, that looks interesting. I'm still leaning heavily towards the AAW kit. I did get a brief text last night with the photo of his smaller power block that comes with the Elan along with confirmation the headlights are fused. The original schematic he sent appears to be out of date or incomplete as it showed they were unfused and there was no provision for the headlight pods limit switches which he also said are included. Note that wiring diagram shows 8 fuses, whereas this photo shows 12. I'm curious what the extra two are for or if those are just spares.

With the orientation of the relays, mounting it behind a revised glovebox may create access issues. Perhaps fabricating a shelf beneath the glovebox with a cover that blends in and hides it from view could work? Regardless, I think it's solvable.

[stugilmour]

Ah, that looks much better.

Given that the Advance headlight loom used four fuses for the headlights, I am guessing that is the situation here? At any rate I am sure he has it worked out.

It all looks pretty solvable to me as well. I agree under the glovey is the most promising. Worth an ask if he can provide a project box or cover of some kind; I saw some posts about this topic but not sure if anything commercially available got highlighted.

I guess a good examination of the existing diagram is in order to see if there are more questions. Hopefully he can supply updated documentation with all the revisions included. I mean, the documentation was the original appeal of the system.

A couple of items I can see. Basically no show stoppers, and very little that impacts the module connections, which I suppose is all that matters right now. More a ‘file for later’ list that comes to mind…

• The alternator connection lists as a GM type. Most currently popular Elan aftermarket alternator setups use a NipponDenso donor. IIRC the NipponDenso alternator uses the Brown/Yellow for the dash ignition light and separate White to power it up. In some cases they have provision for another “remote sensing wire” back to the main +12v located at the starter solenoid where the +12v battery, alternator output, and main loom input wire are joined. Not a big deal to physically add these wires later as the general practice is to run all these wires together across the firewall in sheathing, That’s how I did it. Of course the stock voltage regulator is completely eliminated. This is a bigger detail in the Plus 2 because a lot of them have an ammeter which puts the main charging wire within the dash loom. Anyway, an easy detail to work on during installation as external to the module.
• The tach connections might need attention depending on what you have and whether it is upgraded. Kind of a detailed topic depending on whether you are using electronic ignition, what type it is, and where the module is located. Basically what you want is a clean 12v ignition switched power supply for the module.Pretty easy to pick up an extra White if needed.
• Interesting he shows the brake failure light powered off a green. Pretty sure mine is powered by purple, but it is for a dual circuit Federal system. If your brake failure is a fluid level warning type it is probably better this way? Something I had never considered.
• I would prefer two separate Purple wires off of the module from the courtesy light fuse. The diagram appears to show an external splice or common bullet connector to possibly run additional Purples, although they only show one interior light. Again, this is more an issue with a Coupe because you need a purple to each light, two of which are at the rear of the car. One independent purple to the rear loom block connector makes a nicer job in my view. A single Purple to the dash area should be fine in a soft top.
• Of course the headlight configuration detail is still TBD. Wonder if he makes provision to fuse the headlight relay trigger supply, shown as Blue. Think this is kind of a vestige of the stock circuits being unfused (or I think in the case of some Plus 2’s there was a version with resetting breakers?). Anyway, in general he has power relay triggers being fed off of the same fuse as the relay main supply. I like this better than the way I did it, where I didn’t pay enough attention and ended up loosing a device if a separately triggered relay lost power. For the headlight setup this should troubleshoot ok because if you loose all four filaments you have an issue with the Blue trigger supply, where as if you loose one filament it is likely the individual fuse. Anyway, something to pay attention to when adding any relays.
• Can’t read the radio/accessory wire colour used, but believe White/Pink is standard? Not a big deal as not connected to the module, so can use whatever colour you want. Anyway, I made up a separate small accessory loom that I located driver’s side coming off the ignition key. Use the accessory bus to power phone charging, a Garmin, etc.

Anyway, looks like you have everything pretty well sorted. Hopefully Advance can supply in a reasonable time. I must say his attention to your questions is great.

[JohnCh]

Steve called me today to address the open questions. I really like his support thus far. He misunderstood my question about the headlight pods switches and was unaware of their existence. He said other Elan owners hadn't asked. He also doesn't have a provision for the headlight flasher. Neither of these are big deals for me. I'll either skip them in the interest of adding lightness or figure something out.

Stu is correct on the extra 4 fuses. That powerblock shows the setup with the fused headlights. I did confirm the wiring is for the GM not the Denso alternator, so I'll need to address that. As for the tach wiring, I have a 123 Ignition and previously installed a Spidya module at which point I had run a dedicated white wire. That never worked particularly well and was a source of frustration. Consequently, the tach was sent to West Valley Instruments yesterday to have it properly converted. Fingers crossed.

I'm sure there will be some tweaks required to make this all work, but they sound relatively minor. As for the mounting, I'll figure that out while waiting for the harness to arrive. Most likely I'll 3D print a suitable mount and cover.

[ElanDNA]

John
Somewhere on the forum is a good photo of an installation in the glove box, very neat and probably worth looking out, I cannot recall exactly where but I think it was headed up something like Fuse Box and Relays. I know that is a pretty general heading but hope it may give some idea of how neat a non standard change can be.
Tony

Tony do you mean this photo:

There's more to see here:
https://lotuselan.net/forums/viewtopic.php?f=38&t=38941
Urs

[tonyabacus]

John
Yes that is one that I remember, however there was another which did not involve cutting the glovebox around, the fuse/relay box was fitted on the inner upright edge with wires inserted from the rear, so leaving a tidy appearance and reasonable size space inside the box itself. I recollect it had a clear plastic cover to the front. It was also fitted in a RHD car.

Unfortunately now I am unable to recall how I came across it, but certainly it was whilst looking up fuse/relay information in the electrics section, sorry I can't help more.
Tony