Turn signals go haywire/turn themselves off while accelerating

Matt Rain

Matt Rain

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1985 FJ600 - I've thoroughly cleaned and lubed the handlebar switches and they operate much smoother than they were when I got the bike, but I still can't get the signals to stay on reliably when accelerating - they either start blinking faster, go weak or simply turn off. They'll stay on forever while idling.

What should I check? Relay? Rectifier? I don't know these things.

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Take out the light bulbs out of the sockets and inspect for oxydation. Clean them. Make sure they are seated correctly. Next look where the connectors are [i have a yx600 similar to FJ] mine were under the headlight bucket, and make sure that connectors are not oxidized, and make sure they are actually plugged in. IF that doesnt help make sure the wires are not broken.

The symptoms are of a bad contact, that moves around with vibration.
 
Matt Rain said:
Never thought of checking the bulbs themselves, doh. Thanks.
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Put some dielectric grease on the bulb contacts to save yourself the hassle of doing it again later, cheap insurance.
 
Oh dear. I cleaned the bulbs and all connectors a couple times. Didn't change a thing.

Then I found this gem in my service manual:

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Turns out that I only have a slight issue with my left turn signal going a bit crazy when the RPM changes. Beyond that, both signals are working as designed. *facepalm*

How many of you have self-cancelling turn signals?

What a machine, this thing. *pets old heap of *****
 
I knew about self canceling, but i thought you knew that. What i was going on about though is the FAST flashing indicative of one of the light bulbs not being connected, thus the loose contact.
 
Nah, all contacts are solid. One of them was a bit loose, on the right side (the one that's working 100% correctly), but that was fixed.

Next up is the relay, I don't think I've encountered it yet. According to the diagram in the manual it's somewhere under the fuel tank. Will have to pull it this evening.
 
It's probably the same relay used on the FZR400. There is a sensor built into the speedo housing that gives a signal to the turn signal relay.

When I put my second FZR back from track to street, I reconnected that sensor (to "put it right") and I wish I hadn't. The amount of flash time that it gives me is just short of what I always want, and it ends up cancelling the signal just as I pull up to the intersection where I plan to turn.
 
Yeah, I don't find it ideal, especially in downtown traffic where I may get stuck at the same light for 15 minutes. Looks as though any forward movement triggers the variable countdown mechanism, however it works.

But knowing that they self-cancel by design is definitely helpful. :happy8:

Ashamed to admit how long I've obsessed over those darn turn signals.

Hopefully cleaning the relay connector will fix the left signal.
 
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So... would I just need to disconnect that sensor in the speedo housing to get regular, non-self-cancelling signals?

I'm probably getting rid of the bike before I take my full M road test next year, but worst-case scenario, I'd want to disable that feature for the test. 150 meters of flashing when merging on the highway is too short.
 
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Brian is talking about a little reed switch that sits in the back of the speedo housing. It counts the pulses from a little gear and determines how far you've travelled.
 
I'm sure you could pull it out and tape up the hole (don't want moisture getting in). Maybe a little silicone - if too much is not applied.
 
Still struggling with this. Flashers behave mostly normally, except that they still go crazy from time to time, i.e. flashing erratically, almost dying out then coming back on, etc.

I pulled out the relay and cleaned the connectors. Having ruled out bad wiring/bulbs, could I be dealing with a faulty relay?
 
Update - it was, in fact, the relay that was failing. I swapped it for a used one that came off a slightly newer bike and voilà, no more erratic flashing.

Finally!
 
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