Factory Turn Signals Suddenly Stopped Working

[Tenshots1]

Hey guys,

I just picked up a completely original 1980 GS550E as my first bike a few weeks ago. I went riding today and everything worked fine. On the way home, I noticed that my turn signals had suddenly stopped working. The dash no longer displays the flashing yellow lights and I don't get anything from the lights themselves. From my limited knowledge, I would guess that either the switch itself stopped working or that there is maybe a bad ground for the signals. Note that the rest of the left cluster works fine: horn and headlight operate as usual.

Do you have any advice on where to begin? Do these switches have any history of breaking etc? I figured it would be nice to get a little feedback before I start taking the thing apart.

[Steve]

Does the horn work?

How about the brake light?

No, not silly questions, they are all powered by the same fuse.
Verify that you actually have power getting to the flasher before trying to diagnose anything further.

.

[Tenshots1]

Does the horn work?

How about the brake light?

No, not silly questions, they are all powered by the same fuse.
Verify that you actually have power getting to the flasher before trying to diagnose anything further.

.

Yes, the brake lights, headlight, and horn continue to work.

[posplayr]

If you look at the schematic you want to look for what things are common that would cause all 4 lights to go out. It might even be easier to schetcout a simple schematic of just the circuit path for the blinkers.

The power is in common (guessing you have a single fuze), so there is power to the rest of the bike...... Thats not it, Next
The grounds are all separate so that is obviously not common, .......next
The lights are all separate so it is not burned out bulbs..........next
It affected both sides so we have to look at anything above the directional switch or potentially at the input of the directional switch before it selects L or R.
Most likely item at this point is either a cut wire or the Flasher.

So as Steve suggested, check power at the flasher; If there is power then a.) check for a cut wire downstream or b.) replace the flasher and retest.
If there is no power, look for a cut wire upstream.

If you are as experienced as Steve at diagnosing systems, you do all this in your head without really having to think about it. I just thought I would elaborate on the steps so it is more clear how a methodical process of diagnosis is actually determined.

[gustovh]

I am a simple guy, I would check the fuse first.

V

[posplayr]

I am a simple guy, I would check the fuse first.

V

I'm assuming Steve already knows the 550 probably only has one main fuse.

[gustovh]

My 80 550 has a separate fuse for lights and turns, never had a bike with only one fuse.

V

[posplayr]

Well you got me, seems every time I just assume separate fuses, someone with a 550 comes up saying they only have a single. Anyway, with horns and dash lights working it is unlikely the signal fuse is blown. However, most of the dash lights are headlamp circuit powered so who know.

[Steve]

Yes, the brake lights, headlight, and horn continue to work.

Headlights are on a different fuse, but thanks for checking.

If you are as experienced as Steve at diagnosing systems, you do all this in your head without really having to think about it. I just thought I would elaborate on the steps so it is more clear how a methodical process of diagnosis is actually determined.

I just went the easy route and suggested the first step, but yeah, that's the process.

I am a simple guy, I would check the fuse first.

And you can check the fuse by listening for the horn and observing the brake light. All on the same fuse.
(So is the oil warning light and the neutral light.)

I'm assuming Steve already knows the 550 probably only has one main fuse.

Up through '79, they did, but they had multiple fuses starting in '80. The OP has an '80.

.

[posplayr]

I just went the easy route and suggested the first step, but yeah, that's the process.
.

I think you missed my point; you did in fact do all of that you probably just did not realize it as it happens so fast. The OP certainly would not have grasped it, and before I started thinking it through neither did I.

[Tenshots1]

I think you missed my point; you did in fact do all of that you probably just did not realize it as it happens so fast. The OP certainly would not have grasped it, and before I started thinking it through neither did I.

So now that fuse is ruled out, I'm down to loose wiring or faulty switch right? Prior to this occurance, it did seem like I really had to push the turning signal switch somewhat hard in order to get it to turn on. Is there a way to replace just the switch or would I be replacing the entire left controller ( terminology is lost, I apologize)?

[Steve]

In that case, it appears that something inside the switch is broken.

Depending on what broke (or just got moved out of place), you might just change that part, but it might be easier to just change out the whole left assembly. Unless you have a pristine show-quality bike, there is no need to get a brand-new one, someone here probably has a decent used one that they could sell you.

.

[Tenshots1]

In that case, it appears that something inside the switch is broken.

Depending on what broke (or just got moved out of place), you might just change that part, but it might be easier to just change out the whole left assembly. Unless you have a pristine show-quality bike, there is no need to get a brand-new one, someone here probably has a decent used one that they could sell you.

.

Well it is in pretty good condition. Only 7800 on the bike. Are there any upgrades to the left assembly that people are getting? I hate buying replacement parts. Any other bikes that had compatible/superior left assemblies? I noticed eBay has used replacements for about $30 shipped.

[Steve]

I don't know of any specific "upgrades" that are being done, but it shouldn't be too hard to find a good, used switch assembly.

Your bike does not have self-cancelling turn signals, so make sure that the replacement switch doesn't have them, either.

There are a few models that will have very SIMILAR switches. You might have to adapt some wires to a different connector, but a switch from any of the smaller bikes (<750cc) will probably work.

.

[Tenshots1]

I don't know of any specific "upgrades" that are being done, but it shouldn't be too hard to find a good, used switch assembly.

Your bike does not have self-cancelling turn signals, so make sure that the replacement switch doesn't have them, either.

There are a few models that will have very SIMILAR switches. You might have to adapt some wires to a different connector, but a switch from any of the smaller bikes (<750cc) will probably work.

.

Ok so I finally got some time to play with the bike. I popped open the left assembly and took it apart. Blinker switch looked good with everything intact. I cleaned up the parts a bit and put them back together. Then, I went and checked out the flasher relay. I noticed it was an aftermarket one that the PO popped in there and didn't tie down or anything, so it was jumping around next to the battery. When I listened close and turned on the turn signal, I could hear a single click out of the relay, then nothing. Note that the lights didnt turn on during that click. So, my next job is going to be replacing the relay and seeing what happens.