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1978 R100/7 - Turn signal

SCBuckeye

New member
I have a 1978 R100/7. When a turnsignal bulb is burned out, is the dash indicator light designed NOT to blink?

Just wondering.
 
It's been a while since I burned one out...but I remember it blinking faster with only one turn signal light on. Maybe it's just me...
 
Turn signal w/trailer

That's funny.

I want to pull a trailer so I wired it by disconnecting the tail/stop/blinkers on the bike and going to the trailer. Everything works fine, but when I put on the left or right blinker, the "dash" light does 1 blink and then nothing more. Does this for both sides L/R. However the front flashers on the bike and the rear flashers on the trailer work on just fine.

I thought that the bulb in the trailer may not be high enough amperage so the bike "thinks" that the bulb is burned out.

What I also want to do (I had planned this anyway) is to put a little LED bulb on each side of my fairing up around the windshield so that I am reminded that way anyway. I have a habit of forgetting to turn off the turn signals so these would be the reminder to me.

????
 
IIRC the idea that the dash light blinks once and stops is a feature of the signal relay and bike's wiring. In more simple systems, if a bulb is burned out, the blink rate increases because there's less load on the whole circuilt due to the burned out light and the blinker element heats up quicker as a result.

You might read Snowbum's article on adding running lights...it might provide some background on the issues with adding lights such as what you want to do:

http://bmwmotorcycletech.info/addingrunninglamps.htm
 
IIRC the idea that the dash light blinks once and stops is a feature of the signal relay and bike's wiring. In more simple systems, if a bulb is burned out, the blink rate increases because there's less load on the whole circuilt due to the burned out light and the blinker element heats up quicker as a result.

You might read Snowbum's article on adding running lights...it might provide some background on the issues with adding lights such as what you want to do:

http://bmwmotorcycletech.info/addingrunninglamps.htm

To be honest, I thought it was the other way around. When the circuit through the flasher unit is overloaded (like adding a trailer and more flashing lights) the flasher actually blinks faster as the heat load is greater. When a bulb burned out, the heat load was lower therefore the flasher didn't work or was too slow. When I worked at a dealer that sold boats, and I wired a trailer to a car we almost always had to add a "heavy duty" flasher as the extra lights load caused the original flasher to blink too fast. Less lights caused it to blink too slow or not at all.

In my R100 situation, I wired everything so that when the trailer is connected, the regular motorcycle rear lights are by-passed so they do not work. When the trailer is connected, the "dash" flasher lights up 1 time and never again, but the both front and trailer flasher lights do keep on working. However, when I disconnect the trailer and go back to the standard motorcycle lights the "dash" flasher does work.

I noticed in Max's that the turn signal bulb is a 21 Watt bulb, and I am almost sure that the trailer bulbs are not nearly that wattage.

I am first going to look for a 21 watt bulb to fit my trailer socket and see if that solves the problem.
 
As far as the "reminder" is concerned, doesn't the /7 have a turn signal buzzer? My R100S does......
 
As far as the "reminder" is concerned, doesn't the /7 have a turn signal buzzer? My R100S does......

Mike- I got tired of riding behind him with the buzzer going off, so I convinced him to eliminate it.

It might be juvenile to feel embarrassed by your parents, but that buzzer was just too much!
 
Final conclusion

My problem was this: when I hooked up my trailer lights to my motorcycle, by-passing the mc back lights, I found that when I turned on the turn signals, the "dash" flasher indicator light would only blink once, and then go off, even though both the lefts and both the rights kept on blinking.

Solution: the turn signal bulbs in the trailer were too small (not enough wattage) to trigger the dash flasher indicator to keep on blinking. I think this was BMW's way of letting the rider know that one of his turn signal bulbs was burned out. I fixed the problem by wiring in a new automotive sockets to each of my trailer turn signals and using a larger drawing bulb (almost identical to the regular BMW turn signal bulbs, just with a more modern base). Solved the dilemma. Now the "dash" indicator works correctly as it was designed to do.
 
Mike- I got tired of riding behind him with the buzzer going off, so I convinced him to eliminate it.

It might be juvenile to feel embarrassed by your parents, but that buzzer was just too much!

Do all of you now know why I have gray hair?

I've had to put up with this kid now for 23 years!
 
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