Tuesday, August 25, 2009

E39 Turn Signal Switch Fix

For a month or so now, my right turn signal (blinker) hasn't been canceling itself. I got a hold of mdimbler's Bentley manual to get the switch out so I could inspect it. While helpful, the Bentley covered an earlier model of the switch that merely clips in. Mine required removing the entire steering wheel, four screws, a few wiring harnesses, and THEN 2 clips. No biggie, the Bentley manual got my wheel off for me (it's an amazing, magical piece of literature.) I'm gonna start into a bunch of photos of the real problem and how it was fixed.

Here is the switch in the steering switch assembly. I already pulled off the tilt-wheel switch, it is lying in the car:

Clips to set it free

Inside the top part of the switch. I cracked the switch open to see if I could spot any trouble areas. It is a complex little device, so I was careful not to take apart what I couldn't figure out. This little tab you see here that I depress is the canceling mechanism. It was sticking, so I thought it needed a little lube in there to free it up.

Turns out it was this little broken pin (someone pushing forward on the stick too aggressively while turning the brights on- probably me) that was letting the cancel mechanism get pinched in the housing and not catch properly. You can see where the pin SHOULD have been.

I thought, "Well poop, I don't think I can work with anything this small..." I knew super glue alone wouldn't hold it for long. Then I started thinking of bracing it with a small screw. I thought eyeglasses first, but I couldn't just well pull a screw out of my spectacles now could I? But I did snag an old, snazzy pair of my wife's sunglasses to steal a screw. Luckily they were too long- she would have been mad ;). I ended up using 1 of 2 suitable screws from an RC heli I fly. This screw just held on the cockpit bubble, no biggie. See the size next to a micro Phillips screwdriver.

I drilled out a hole with my smallest drill bit- 1/16th", filed down the injection molded ribs with the Dremel, and screwed the pin back on. I was thinking of also using super glue, but it holds very well with the screw, and I didn't want the glue to cure before I got the pin screwed on straight.

All back together and ready to put on the car.

I took a short drive after the install, taking as many right turns as possible. Fixing that pin made all the difference in the functionality of this switch. It was highly annoying to have to cancel right turn blinks myself.

Long writeup for something so small- I know. But the moral of the story is, "Treat your car nice. One little foul movement can break the beast!"

1 comment:

Anonymous said...

Great writeup mate and just in time for me. Its quite often the small simple things that render something broken.
Good on ya, saved me a bit of frustration not knowing whether its a fix or replace job.