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Strange response from turn signals

20774

Liaison
Staff member
I was headed to the dealer to get an inspection over the weekend...turns out they were not available, so I just got to enjoy the ride. I thought there might be an issue with my turn signals...they haven't been responding when I flick the switch on the handlebars. The instrument pod lights up, but it doesn't switch on-off. All of the lights are working...it seems just the relay doesn't toggle...but hey, the buzzer works!!

As background, the rear signals are stock...the front signals have been transferred to the Luftmeister fairing. Power to the lights is through the umbilical from the headlight through the 9-pin connector in the inside part of the fairing.

During the ride, I did some investigation. It seems that the signals work, albeit a bit slow in toggling, when the bike is either just on battery (engine not started) or idling at a light. If I'm running down the road pushing 14v from the alternator, the relay doesn't want to work. I unplugged-replugged the fairing connector and also sprayed some cleaner/lubricant in there. I recheck yesterday, and in the garage, with the key on engine not started, the signals work reasonably well. How can that be?

The up-side might be that when getting the inspection, the engine is not on...I just have to turn the key on and show that things work.
 
I confess right up front that these type of electrical problems are an enigma to me. Gremlins.

However, if I understand correctly, the signals flash at lower voltage (off battery or idle) but don't flash when at 14 Volt (at higher RPMs).

I would try first, is looking at the flasher unit. Take apart, and clean out, and the connectors.

On some automotive types, the flashing is caused by a bi-metal strap that connects the contacts in the flasher unit. One of the metals expands to heat faster than the other, which causes the metal strap "bend" to the side, breaking the contact. Thus cooling off. Then it contacts again, and the process goes on over and over until you shut off the turn signal. I am wondering if the higher voltage might be affecting this? Doesn't make sense to me, but worth a look.

The other thing I was thinking. About 3 or 4 months ago (you may remember), I had trouble with mine. I concluded that when a bulb is out (or disconnected), the dash light will flash once and then nothing. During that process, I studied the wiring diagram a lot, and (as I remember) it seemed to me that the turn signal wiring circuit was bazaar. Adding to the weirdness was the way the buzzer was wired. However, the buzzer only worked when the bike was in motion and the turn signal was still on. I am wondering if the buzzer circuit is affecting the situation? Since it is designed to work only when in motion (when engine is at higher RPM (and higher voltage)) could this be affecting anything. I would remove buzzer itself and see how things work.

I am sorry because all of this is conjecture on my part, and I am sure you have already thought of stuff like this, but I know just how unnerving these types of problems can be.

Please let us know when you finally do figure out the problem.

JC
 
The circuitry on the bike is as I received it...I'm second owner. It used to work but for some reason over the years, it's not be working properly. It's been a low priority because I don't use my signals all the often...did I just say that?? :deal Yes, the buzzer works when not at idle and the clutch hand lever out. The presence of the buzzer doesn't seem to make a difference as far as I can tell. My first thought is to replace the relay/trigger/flasher but IIRC it's in the headlight shell...not that fun with a Luftmeister fairing installed. :banghead
 
The circuitry on the bike is as I received it...I'm second owner. It used to work but for some reason over the years, it's not be working properly. It's been a low priority because I don't use my signals all the often...did I just say that?? :deal Yes, the buzzer works when not at idle and the clutch hand lever out. The presence of the buzzer doesn't seem to make a difference as far as I can tell. My first thought is to replace the relay/trigger/flasher but IIRC it's in the headlight shell...not that fun with a Luftmeister fairing installed. :banghead

I think that I have the same bike/fairing as you do (except for the Snowflakes). I have the umbilical wiring cord from bike which has a pretty-much quick disconnect. I also have a couple of other wires going to it, but I put in a disconnect on them as well - the point is, is that I can remove the fairing with 4 bolts, and 2 disconnects. Takes about 5 minutes - just for this very same reason - I had to get into inside the headlight shell and got tired of it being an hour process.

Anyway, I still vote the flasher unit is going bad from age or something.

My only problem with mine lately, was when I had the engine conk out for a split second as well when I hit the turn signal - but only a couple of times. I found out the issue (not logical to me, but found by near accident) was the multi-connector block just under the front left of the tank. Several relays and an always hot wire (so be careful with that screwdriver!). I took apart both relays, cleaned and reassembled. Cleaned each of the terminals on the relays and wires. Put everything back together and used some zip ties to hold the relays firmly in place. Problem never occurred again.

Another thing to check (as I did with mine) is to simply disconnect the fairing - just to check the rest of the signals to see if they work. That would at least isolate the fairing to see if it is the problem. Problem here is that the signals are designed NOT to work when one or more of the bulbs are disconnected.

Not much help, I know, but LOTS of empathy!
 
I, too, have specific wiring in the left side of the fairing. My voltmeter is wired directly to the battery and the ground for the add-ons in the fairing (clock and voltmeter) are run out to the frame...unfortunately, I didn't build in quick disconnects and the ring terminal won't feed out the bottom hole in the fairing...not great thinking on my part. I also have a cutoff switch for the voltmeter. So things are a bit more complicated...which is why it's not just the four bolts and the one connector.
 
The signal is working better after cleaning the terminals, although it takes about 2 seconds between cycles. In the end, it didn't matter...just got my inspection. All we did is kick tires and talk bikes...then he slapped a sticker on. :banghead I guess I'm something of a "known" commodity at the dealer, they must figure it's OK. That and he makes $1.50 per inspection...he needs to get back to "real" paying work!!
 
The signal is working better after cleaning the terminals, although it takes about 2 seconds between cycles. In the end, it didn't matter...just got my inspection. All we did is kick tires and talk bikes...then he slapped a sticker on. :banghead I guess I'm something of a "known" commodity at the dealer, they must figure it's OK. That and he makes $1.50 per inspection...he needs to get back to "real" paying work!!

Did you clean just the connectors where the flasher unit plugs into the wiring? Did you try to take the flasher unit apart, and clean out in there?

Just askin...

Someone once told me that there are flasher units that fit sold at AutoZone. I thought you could try one of them to see if performance is better.
 
No, I just cleaned the contacts on the multi-pin plug from the wiring harness into the fairing. It's on my list at this point for the next time I've got the fairing off. I'll track down the flasher unit and replace with new...I guess 30+ years is good enough. I'll get OEM...yes there are other flasher units but in some cases you have to modify the wiring or internals of the unit and you may/may not get the "logic" BMW built into the flasher that provides insights when bulbs fail, etc.
 
No, I just cleaned the contacts on the multi-pin plug from the wiring harness into the fairing. It's on my list at this point for the next time I've got the fairing off. I'll track down the flasher unit and replace with new...I guess 30+ years is good enough. I'll get OEM...yes there are other flasher units but in some cases you have to modify the wiring or internals of the unit and you may/may not get the "logic" BMW built into the flasher that provides insights when bulbs fail, etc.

To be honest, even though I am willing to substitute on occasion, I would also get OEM for this item. Can't be that much of a price difference!
 
I don't know which bike that you have so I will suggest that you check & clean the points where "ground/earth" are maintained (turn signal brackets in particular). Second as I recall the special turn signal relay that you apparently have (one blink for a bad bulb) is a lot more money than an almost comparable auto unit. The cheaper auto unit can be made to work, minus the one blink bulb out warning. I too think that if you need to replace the unit, stock would be best.
 
I don't know which bike that you have so I will suggest that you check & clean the points where "ground/earth" are maintained (turn signal brackets in particular).

On my /7, the ground isn't provided by the mounting bar, but by a separate ground wire to each of the signals.
 
No, I just cleaned the contacts on the multi-pin plug from the wiring harness into the fairing. It's on my list at this point for the next time I've got the fairing off. I'll track down the flasher unit and replace with new...I guess 30+ years is good enough. I'll get OEM...yes there are other flasher units but in some cases you have to modify the wiring or internals of the unit and you may/may not get the "logic" BMW built into the flasher that provides insights when bulbs fail, etc.

Did you happen to look up the price of a factory turn signal flasher? Whew! Sticker shock!
 
Having the same thing with my R75/6

This is valuable info

http://www.pt-photos.com/relay_bmw_turnsignal.htm

Found when I took the relay apart and used 320 paper on the contacts and the bar contact that operates the indicator light all is well. Relay was full of white dust?

What I thought was a bad ground or feed was just a dirty relay.

Scot
 
I just found the pictures on the web when trying to find a part. Another owner continues to help.
 
This is valuable info

Found when I took the relay apart and used 320 paper on the contacts and the bar contact that operates the indicator light all is well. Relay was full of white dust?

What I thought was a bad ground or feed was just a dirty relay.

Scot

Wow, what a great job.

This is what I like to do. Take them apart. They aren't usually rocket science in there. However, I clean them out, and dress the contacts, and adjust gaps. The biggest danger is breaking the little "stator" wire around the coil.

I don't usually do as thorough a job as you did! Yours is good to go for another 35 years!
 
Wow, what a great job.

This is what I like to do. Take them apart. They aren't usually rocket science in there. However, I clean them out, and dress the contacts, and adjust gaps. The biggest danger is breaking the little "stator" wire around the coil.

I don't usually do as thorough a job as you did! Yours is good to go for another 35 years!

The pictures are not me, I just polished and cleaned mine. Found the full rebuild sequence on the web. May have to find the guy to make sure he gets credit.
 
The pictures are not mine, I just polished and cleaned mine. Found the full rebuild sequence on the web. May have to find the guy to make sure he gets credit.

Originally, I thought these pics were yours, but later figured it out. But, hey, they show how those old parts can be redone to be as good as new if one has the time and patience.

Still, a general take-apart and cleaning can do wonders too. I've done it on many solenoids, relays and flasher units. Some are not really made to be repaired, because one has to bend tabs or take out rivets, but those can be carefully replaced with small screws, or put back together with glue, epoxy, or simply just a small cable tie.

I think most of these types of units fail, not from usage, but from moisture from the air, or for those living close to the oceans, from salt in the air - leaves that whitish powder inside.
 
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