On the left, cigarette-lighter outlet: plastic body and lock ring, guaranteed-to-break rubber cover "hinge," press-fit back plate. On the right, German-made DIN receptacle: metal body, brass lock ring, rigid cover with spring-loaded hinge. The cordless automotive cigarette lighter was patented 90 years ago, and assumed its present configuration in 1956. I know for a fact that by 1960, car campers already had a range of 12-volt appliances from which to choose, such as the Boilmaster Junior Compact Kitchen coffee percolator featured in my old copy of The Ford Treasury of Station Wagon Living.
That means that for five decades those wishing to use their vehicles’ cigarette lighters for anything besides igniting a Pall Mall have put up with the “UL Standard 2089” 12-volt plug to try to get DC power to their portable percolators, tire pumps, GPS units, inverters—even their National Luna 74-liter double-door fridge-freezers.
Are we really that submissive to the dominant paradigm? If GM reintroduced front drum brakes and two-speed automatic transmissions would we all go, “Well . . . okay!” We’re talking the same era here.
Anyone who has ever used a standard auto lighter receptacle as a power outlet knows they’re garbage for that application. It’s impossible to tell when the positive post in the center of the male plug makes contact with the positive tab at the back of the female unit, and—especially if your appliance’s plug doesn’t have a spring-loaded post, or if the spring has seized, as most do after about two months of use—contact can be lost with no warning except when you stop for a cold Coke three hours later and find only tepid Cokes in the fridge. Worse, the most common aftermarket cigarette-lighter-type “power outlets,” which many of us install to run extra equipment, are constructed with a plastic back plate for the positive contact that is a simple press fit into the plastic body. Push too hard on the plug and the whole back end of the receptacle pops off.
There’s a better way, and by this time European readers and a lot of American BMW GS riders will be nodding their heads knowingly. They’ve been happily using the DIN (Deutsches Insitut für Normung) 12-volt plug system for years. The DIN plug, while more compact than the cigarette lighter (11/16-inch mounting hole versus one and a quarter) is significantly more rigid and wobble-free. The dash (female) socket grips the positive post of the plug with spring-loaded fingers—push in the plug and it snaps home with an authoritative click. No risk of pushing too hard, no risk of accidental disconnection, even on the roughest roads.
After years of muttering and cursing, and a brief consulation with my friend Brian DeArmon, I finally made the switch, courtesy of our local BMW motorcycle dealer in Tucson, Iron Horse. It’s easy to do, although if you want to install a DIN outlet in a hole made for a cigarette lighter you’ll need to buy or fab a thin washer to reduce its diameter. On the dash of my FJ40 I decided to leave the old receptacle in place so I wouldn’t have to use an adapter when borrowing or testing appliances equipped with that plug. I had a perfect place just below the old receptacle to install a DIN unit, where my stock dome-light switch was located. Since I use a Hella map light for a dome light now I had no need for the switch, so I simply enlarged the hole and installed the DIN receptacle. For now I just siamesed the wires to both receptacles and use a single fuse, since I never run two heavy-draw appliances from the dash at the same time.
FJ40 dash with cigarette-lighter outlet, stock dome light switch underneath.
DIN receptacle in place, wired in parallel.
If you don’t have a BMW dealer nearby, you can get DIN plugs and accessories from a company called Powerlet. The standard socket is part #PSO-001, and there is a selection of plugs, including a nifty low-profile right-angle version. They even have a pretty decent-looking cigarette-lighter plug if you’re a fan of two-speed transmissions, or would like to leave one standard socket in the vehicle as I did.
Swapping plugs on your old appliances is easy, too. Some 12V fridges come with convertible plugs; a red spacer allows use with a cigarette lighter; remove the spacer for a DIN receptacle. It works okay, but switching to a DIN-only plug is more compact and stronger.
Straight and right-angle DIN plugs are available.As with many such simple and effective modifications, my only regret has been, why did I wait so long?