I darken the sky with lightswitches

The old switch panels in situ

The old switch panels in situ

I’ve been working for some time, in any suitable moment, on replacing the separate switch panels that control the auxiliary lighting and other equipment that I’ve added to my Land-Rover.

The back of the old panels

The back of the old panels

The old panels had so much wiring crammed behind them that they had become very hard to re-attach to the vehicle if I ever had remove the for alterations and maintenance, so I was careful to design the new one to be easier to work on for the future.

Construction begins

The metalwork

I made it reasonably modular, with each group of switches on a metal plate that unscrews, with connections that plug into the framework of the switch panel, so each piece can be removed easily for alterations. The old system was undocumented (or perhaps I had written it down and lost it) and needed painstaking wire tracing whenever I needed to do anything to it, so the new one is systematically documented down to every individual connection, organized, of course, by Emacs’ org-mode.

The mechanical construction is of 3mm aluminium. I got the frame welded by the Small Works department of my local hardware store, Mackays.

The switch panel under construction

The wiring in progress

Once that was built, I started to add connectors, switches, and wires. It’s not as neat as I had hoped it would be, but the main “loom” across the front pulled into shape quite well with cable ties, and I can tidy up each sub-panel later.

The panel folded down for maintenance

The panel swings down for access to the framework wiring.

As well as each sub-panel being removeable, the whole panel hinges downwards for access to the framework wiring, although it’s quite cumbersome to lower or raise it.

I made up a test lead, a short section joining a male and a female 8-pin connector, and teeing off to a box of LEDs and a few switches. I can unplug any 8-way connection and insert this device, to find what’s going on at that point; I can also use it to inject a supply to see what happens.

There’s room for future expansion, too: between stretching the vehicle and adding an electric rear axle drive system, I plan to put a computer (probably some kind of beagleboard) into the switch panel; I’ve designed in provision for display screens with menu buttons down the sides, for both driver and navigator seats. On either side of the driver’s screen position are holes for mounting more 52mm dashboard gauges (the standard size): I’ll probably displace some of the standard gauges up to there from the dashboard and add a tachometer and an oil pressure gauge to the dashboard.

The new switch panel in situ

The new switch panel, in situ

The project took a lot longer than I expected, so it feels all the better to have completed it! Not that such a project is ever complete; for example, you can see that there are holes for more dashboard-style gauges, and space for an LCD screen for the driver and one for the navigator, with a column of holes for buttons on each side of each screen position.


3 Trackbacks

  1. […] it into a wire at a connector, to see what’s going on, and to run tests. I’ve been using this technique already, and recommend it […]

  2. […] I’ll paint the whole interior white, apart from the parts made from chequerplate, and the switch panel which is staying black. I’m not sure why primer is such a revolting shade of pink. Perhaps […]

  3. […] and re-fit the winch (this evening, I hope); fix a few bugs in the wiring; re-connect the ceiling switch panel. I’d like to get the steering guard back on before I do the off-road course at Billing, too. […]

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