LEDs for Turn Signals -- a Mystery By ellpee (Read 484 times)

[ellpee]

Working my way through replacing as many bulbs as possible with LEDs, and just got four 1056 equivalents for the turn signals. Put the back ones in, all good, nice and bright. Put the first front one in, wouldn't light up at all. Reversed it in socket in case of polarity issue, nada. Put old incandescent bulb back in, lit up normally. Took an extra, identical front socket I had in my leftovers box, put the LED in, jumpered it straight to a 12v battery, nada. Reversed it in the socket, nada. Touched the LED bulb directly to the battery's + pole, jumpered from the - pole to the side of the LED, lit up.

So the LED bulb is fine, but for some reason it won't work in the front turn signal sockets. Come on, electrical gurus, let's hear your best guesses on why that might be. Physically they look pretty much the same as the rear sockets, so WTH,O?

[tvnacman]

The pins sometimes need to be bent to line up with the contacts in the sockets . When I was testing the leds that is what I found , then marked the positive side . That was for the wedge type T10 168 type base . If you look at the contacts on the bottom of the push and twist type . I have seen them come where the contacts are misaligned it relation to the locking tabs (compare to working bulbs) .

John

[ellpee]

Well, these are standard bayonet sockets, so the + contact is at the bottom and the - contact is the entire side of the bulb base. Will be looking at it more today, am totally puzzled that they won't work in those sockets but are otherwise fine. I did discover just now that they are polarity-aware, + must be + and - must be -, but no way to screw that up with these bayonet bulbs as far as I can see.

[ellpee]

SOLVED!!! After considerable experimentation. Wires going to front turn signals are yellow and green -- yellow goes to the center contact at bottom of bulb, green goes to side contact, i.e., entire sidewall of the bayonet base of the bulb.

Generally speaking, one likes to believe green wire = G = ground = negative side for polarity purposes.

On both of my front turn signals -- readers beware, this may ONLY apply to the 2011 Roketas that were assembled the day after a really, really big celebration, when the assemblers had a massive hangover, and maybe only to my scooter, because they hate me -- the GREEN wire carries the + current from the battery, by way of whatever stops it makes enroute (ignition switch, handlebar switch, etc.), while the YELLOW wire serves as the connection to ground.

Standard incandescent bulbs could not care less -- juice in, juice out, it's all good when you're running those. But LEDs, being polarity-aware, want the "in" coming from the bottom and the "out" departing via the side.

So, the cure for my problem was to snip both of those wires and switch them, green to yellow and yellow to green. After that, all good. LED's lit up when they were supposed to (and bright, bright, bright compared to OEM), be it via the turn signal switch or via the emergency flasher switch. I suppose I could have also bought new connectors and reversed the wires, but since I didn't know where to get those kinds of connectors and didn't want to bother, snip/twist/electrical tape did it for me.

So, in the hope this discovery will make 2014 a better year for all scooters that are the Roketa MC-54{whatever}-250{whatever} by whatever other model name they may bear out there on the Wild West Chinese scooter market, Happy New Year. Me, I still have some wires to cut and twist and wrap before the ball falls and the corks go "POP"! But for anybody who makes the migration to LEDs in any socket, learn from my tribulations. LEDs want + and - where they are supposed to be, and you canNOT take it for granted if you're driving a Chinese scoot that the guy on the other end was not colorblind, or stoned, or hated guailo. If it doesn't work on the first try, check your + and - situation before freaking out.

(PS -- once you get it right, I'm really liking the LEDs, very bright and presumably drawing a lot less amps from my already over-stressed charging system. Not cheap, but what's the price of being stuck alongside the highway about 50 miles from civilization because your electrical takers ran down your one and only electrical giver?)

Oh, BTW, the amber 1156-equivalent LEDs I bought blink at the normal rate, no extra load resistor needed. Maybe it's built into the bulbs, or maybe they just work without it. But on my scoot at least, they work fine right out of the box.