Seemingly Unusual Flasher Relay Issue

[bmwbmwbmw]

I have done quite a bit of googling trying to find info on this, but found only unrelated flasher timing issues instead, so here I am, joining BMWMOA:

I flipped on the left turn signal, heard the slightest pop sound, and no left turn signal (front, rear, or idiot light indicator) has illuminated since.

I have tested bulbs, fuses, all turn switches (at the relay plug pins), and visually inspected the insides of the flasher relay looking for burned up spots or nasty smells. The right side functions just fine for turn and hazard indicating but nothing ever from the left. I have never had any problems or weirdness of any kind from signals or any lighting.

My only attempt at actually testing the relay was listening to it- I could hear it making (extremely quiet) electronic noise in time with the right turn signal, but silence for the left, leading me to think the relay has failed.

I purchased a used BMW relay on ebay for $75, but I'm afraid if I don't find some issue before installing it that it will have the same fate, and $150 for a new one per failed attempt after that.


Bike details-
-1996 R1100R
-6000 miles, 5000 of which within the last couple years, no issues of any kind
-No rain/water ever
-Meticulously maintained and adjusted, always clean and well kept
-No modifications to electrical system other than safety blinkers added to brake lights (system works fine, unrelated to issue)


If anybody has ideas on causes for this, I'm open to suggestions on troubleshooting.

 

[PGlaves]

I would try to test the left turn signal circuitry manually, checking for a short to ground. If everything checks OK then I don't see a choice but to plug it in. You can apply 12v at the relay socket to the supply connections to the bulbs.

 

[gsaddict]

As Paul said.
When applying the 12v use a series lamp (like an 1156) to limit the current in case there is a dead short in the wiring.

 

[dbrick]

I think your bike's flasher relay is OK. If it were bad, the right side lamps wouldn't flash normally. Because the right side works, the flasher unit itself is OK.

There's something awry in the circuits which feed the left-side lamps or dash indicator. Could be an open connection, or a short to ground, and it could be in the wires or in the left-side handlebar switch (I think this bike has separate switches for left and right).

 

[bmwbmwbmw]

Solved

I did as you all said (great idea to use series bulb) and tested the circuit.

I tested the circuit from various points with a multimeter and with a DC power supply and everything checked out/powered up fine except for the flasher again: I put in a used flasher that arrived today (ebay/parted out rt) and everything was like new again. I'm assuming one of the 7000 tiny transistors in the old one must have gone bad, and I definitely didn't want to spend a whole evening testing all of those little things. At least the fix was simple.



Thanks for the quick help. I'm glad to see that this forum isn't filled with loud amateurs. I have been avoiding online forums for years because of dealing with that garbage but BMWMOA seems to have some real gems of information and very experienced people.

 

[dbrick]

Interesting. I've never run into a flasher that has left-right differentiation in it. Perhaps it's related to having one unit do both turn flashing and all-four-lamps hazard flashing.

Good work on getting things working again!