19 May 2009

Motorcycle safety, part II

All that earlier work got me nice LED turn signals, but not DRLs (Daylight Running Lights). Today I removed the headlight from the "bucket", revealing the spaghetti mess of wiring you can see to the left. Just about every electrical circuit on the entire bike passes through this bucket, but it was pretty easy to identify the turn signal wires since the turn signal stalks run right into the bucket.

Now comes the challenge. Normally, the blinker relay sends voltage to the turn signal bulbs to light them up. However, if you set them up as DRLs, the bulbs then get voltage all the time and you need to blink them off when you use your turn signals -- this is, of course, backwards.

To "invert" the signal, I used a trailer light adapter. Trailer light adapters exist because most vehicles have three wires: stop, left turn, and right turn. Trailers just have two wires going to two lamps though. This saves money on wiring and lamps, but as you can imagine, there's an extra step to make three signals transform into two signals. The solution requires a little XOR digital logic, which is a little complicated to make from scratch but you can easily buy a plug 'n' play solution prepackaged into a little box. You can pay $100 for a motorcycle specific DRL box, or you can pay $16 at your local U-Haul for a trailer light adapter that does the same thing. I, of course, went to U-Haul. Actually, I first bought a cheap one online but it wouldn't fire LEDs so I wasted some time and money there. All new U-Haul trailers have LEDs so U-Haul's adapter supports LEDs just fine.

Basically I just cut the wires going to the turn signals, and inserted the box in between the turn signal voltage supply and the bulb. This still just gives you normal signals until you connect the "brake" wire on the adapter box to any ignition-on wire: now the adapter will think the brakes are on all the time, and light up both lamps all the time (until you turn a blinker on, and then that one side blinks off). The adapter box was a tight squeeze into the headlight bucket, but it just barely fit.

The LEDs do not cast an even light like the old bulbs did, instead they concentrate most of their light in a couple of directions. From the direct front, they're not very bright but that's ok as my headlight will always be on and is much brighter than the DRLs anyway. However, once you get off to the side a little bit, the LEDs shine nicely. These pictures were taken in the evening, so they are not going to seem as bright in broad daylight but I still think these will give me a nice bit of added visibility to other drivers.

1 comment:

Spectacular Six said...

While you are in handy man mode; I don't suppose you want to find a free/cheap riding lawn mower and fix it up for us? We would reward you awesomely!!! (I have officially mowed as much or more than Paul this year, and boy, we need one!)