Turn signal Issue

[bbelk]

On my 1975 R90/6

The turn signals work fine. The indicator light is weird. When I start the bike the turn signal indicator comes on and stays on for a few miles and then goes off. It doesn't work after that even though the main signal bulbs are working just fine.

The relay is a four pole thing that I have not looked inside of. Can it cause the problem with the indicator. Is there a cheap new replacement or do I need the original part.

Brad

Edit to add: MaxBMW has the relay for $85 which seems a little high to me.

[bbelk]

.....and mine has B, E and L terminals.

You prolly wrote your name on it and the K rubbed off?

After all the helpful input (from three or four years ago), its all back together and works!

[Ken in Oklahoma]

After all the helpful input (from three or four years ago), its all back together and works!

Apparently you're going again. Good! I have had problems with that relay myself, on a couple bikes (/6 and /7). I have come to hate that relay because sometimes it would work and sometimes it wouldn't. Once (or twice) I popped the cap off of the relay to see if there was anything inside that might be the culprit. What I saw looked a bit like an old transistor radio. I was expecting something much simpler, akin to a simple flasher. As it turns out that relay has a lot of features (which I don't remember fully, but one feature was to alert you to a burned out bulb). And sometimes the relay would work for a while and then not work, for no apparent reason. And you're right, they are terribly expensive, then and now. What I did then (on my R75/6) was to get a simple three pronged auto turn signal relay and modify the wiring to suit. You, being electrically adept could do that as well, if it should happen again.

My R100/7, which uses the same relay, also gave me problems and I just couldn't do anything to make things work. This won't be your problem but eventually I discovered that the wiring bundle going to the tail light and turn signals had been severed for some reason and then put back together. The problem was a cold solder joint to a wire feeding the right turn signal. Cleaning up and resoldering the joints fixed my problem.

Ken

[Ken in Oklahoma]

After posting above I discovered that the use of an automotive flasher had already been addressed. I hadn't read this thread. So rather than to edit what I posted just now I thought I would just add this exclamation:

OOPS!

Ken

[bbelk]

I found answers I was looking for in threads dating back to 2010. The two new things I learned that might be interesting to someone researching this problem are:

1) Google finds things on the Boxerworks forum better than the Boxerworks search does.
2) There are at least three choices in newer cheap three pole flashers. The one that works is the one with poles labeled P, L and X.

My own notes taken from one of the earlier threads includes this:

Terminal P = Blck/White wire - (goes to dash turn indicator) - old relay # KBL
Terminal L = Green/Yellow wire - (Load - to signal indicators) - old relay #49a
Termina X = Green/Black - (+12v) - old relay #49

The left over wire is old terminal #31 (ground) - don't need - just tape it off

[SteveD]

Brand?

[dwerbil]

Found this on the web...
"As a reminder, the pricey OEM turn signal flasher on the old airheads like my /7 can be swapped out for a "Tridon Stant" 12 volt 3 terminal #550 thermal flasher available for under $5 from any auto parts store.

The new flasher will have a "P" an "L" and an "X"...you want to plug the wires from the new socket into the existing flasher socket...match the "P" to the black/white wire (your dash light indicator)...match the "L" to the green/yellow wire (the "load"...i.e. the turn signals)...and, the "X" to the green/black wire (+12V supply). The fourth prong (that the new flasher won't have) is brown...for ground...the new flasher doesn't need a ground."


....I've had this fix on my /7 for over 12 years. Yes, this fix over the OEM flasher does not let you "know" when a turn signal bulb is out; big deal...I've not had to replace a turn signal bulb in 25 years or so.

[bbelk]

Brand?

All the new cheap relays at the one auto parts store I went to were the same brand. They had different item numbers, which I did not record.

[bbelk]

flasher available for under $5 from any auto parts store

Well - it was $12.

When you add the cost of the wrong flasher that I bought first it comes to $26. Still cheaper than the $85 OEM.