25/04/2026
Now this is an illuminating natty little doo-dah!
Well, it’s a courtesy light dimming module to give it a proper name…
I’ve been working on more electric trickery and it’s time to deal with the courtesy lights. It’s taken me a while to get round to them because (a) they are earth switched which is a relatively new concept to me and (b) I wanted to get the guts of the dashboard electrics sorted before getting onto the “nice haves”. Oh and I also needed to sort the under dash trays which have been loitering in the boot out of sight for a long time now and needed the mounting method finalised (rubber lined p-clips).
Key for me on courtesy lights is to have a fading out effect and a delayed cut off. I know this can be done with delay relays and such like but I came across this natty little solid state device on fleabay that looked worth a shot. Not the cheapest thing on earth at £12.50 each plus £6.50 postage from Romania, but it worked out at about £15 each for two which isn’t a million miles away from the cost for wires and relays.
Anywho, wired it all up and tested it with a 9v battery. The moment I connected it the courtesy light went on and stayed on. Bu**er. Spent two hours checking wiring, taking it all apart, re-wiring, checking continuity. No change. Bu**er again. Tea break needed in my new Hela / unofficial GD mug (more of that elsewhere).
Whilst supping on the aforementioned nectar, the little voice at the back of my tea-infused brain came to my rescue. Amazing what a dose of builder’s tea (strong, white with one sugar if you’re offering) - the module has a variable delay setting that you dial-in with a small potentiometer on the circuit board. Perhaps it turned up to 11 (if you know you know)?
Well to cut to the chase it was - turned it all the way back to the left, then backed it off a bit. Tried again. Still lit up immediately on connecting the battery but then it faded out. Wowser. It worked and did exactly what was promised. Turned the pot to about a 20 second delay and all is good. The initial lighting up is essentially the unit charging the circuit’s capacitor and doesn’t happen after the initial set up.
One small downside is that the lights fractionally dim when it switches over from battery to the dimming controller, but I can live with that in the greater scheme of things.
Now to wire it all in properly and fit the manual override switches to the ends of the dash board for each of the driver and passenger to have individual control of their own courtesy lights. I’m using a blank latching aluminium billet switch from Car Builder Solutions to match the rest of the switches - wish they did one with a proper courtesy light logo on it but for now it will just be a blank button. I might be able to get someone to laser engrave a courtesy light label onto the blank at some point in the future but for now I’m fine.
A few pictures below of the device and a short video of my jury-rigged set up showing it in action. And yes, my courtesy lights are green but so is Hela😈. All part of the overall theme.