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Signal relay

D

DS74BMW

Guest
I've noticed in the past few days, with a lot of in-town riding, that the turn signals get very weak waiting at a traffic light; they then seem to be OK after no turns for a while.

Is the signal relay going bad? My experience with auto relays is that they either function, or don't - I'm not familiar with BMW's. All other electrical functions are fine.
 
I suspect that your voltage is dropping at idle which slows the speed of the flashing. The factory Airhead charging system really does very little till about 3,000 rpm. At 3,000 and above it is still kind of anemic by modern standards, but will pick up the flashing speed somewhat.

Keeping your battery topped off with a battery tender or somesuch between rides can help. It's also possible that your electrical system may need some maintenance.
Alternator, battery, connections etc.

Unlikely that it is the flasher relay.
 
Sounds just like the turn signals on my '77 Honda 750A. It is the charging system and state of your battery that affects this. When bike has been ridden at higher rpms for a bit, the turn signals will work fine. But keep the rpms low, and soon the battery is discharged to the point that the signals cycle more slowly, or in the case of my Honda, they stop all together. Then light turns green, and as I take off from the stop, the turn signals begin working again.

Unfortunately, the manufacturers are really good at providing second-rate charging systems that are not capable of keeping the battery fully charged.
 
Thanks, guys.
I will go through the connections; the battery is a fairly new BMW mfr, maybe 2 yrs old at most. I'll try keeping my Battery Tender on it between rides to note results.
 
Typically, flasher relays will act erratically as they fail. Blinking faster on one side than the other. My /5's always have exhibited the xlow down. Try spinning the motor a little faster, with signal on - Maybe that's why the HD guys do that!
 
Typically, flasher relays will act erratically as they fail. Blinking faster on one side than the other. My /5's always have exhibited the xlow down. Try spinning the motor a little faster, with signal on - Maybe that's why the HD guys do that!


Yeah, just be sure you take off your mufflers before you rev 'er up!!! :laugh
 
I was able to get about 3 years out of one of those "Official" BMW batteries with regular battery tender usage. I have had much better luck with the Yuasa. I was very disappointed.
 
The turn signal flasher in your bike is supposed to flash at a consistent rate down to about 10 volts; about any time there is enough voltaage available to run the motor. I'd try a new flasher relay.
 
Update:

This weekend, I checked connections and put my Battery Tender on it for a while. The battery was up to charge, as the tender went into "storage" mode in no time.

What I did discover, however was that the signals themselves work fine, it's the indicator light on the instrument panel itself that quits flashing after about 4 - 8 flashes. It has a new #168 bulb in it, which I put in about a month ago. At that time [when the indicator light did not work at all], one of the two tabs on the printed circuit board [which contacts the bulb holder] was broken off. I repaired it by making a new tab from brass shim stock, and inserting it into the circuit board, and it worked fine. I don't know if this is the problem, or not.

The signal relay has a 'stronger' sound to it when the indicator bulb is working, but seems to diminish in sound when it is not. The signal lights themselves [on the stalks] continue to work with the same frequency and intensity.


The signal relay appears to be the original, or quite old, judging by the appearance.
 
The signal relay appears to be the original, or quite old, judging by the appearance.

So am I, but I keep working too!

Resistance has a lot to do with flasher's rates of operation. Accounting for the increase/decrease in sound. When a bulb fails they flash very quickly.
 
i just had what appeared to be a flasher relay problem on my RT. The lights had started flashing super fast. After replacing the relay, though, it actually got wose, with intermittent rear signals not flashing.
Turned out the connector to the tail, which happens to be near the battery, was really crudded up. After cleaning/lubing the connector with some stuff from an electronics shop, everything works fine. i even put the old "failed" relay in, and that works just fine.
So nowI learned something, and have a spare flasher relay to gboot.
 
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