Bonneville America Forums Forums Technical Forums General Tech Electrical help needed!

When I took the bike out today my horn, brake light, and turn indicators were out. These are all on the same 10 amp fuse. When I got back home I checked the fuse and it was blown. I cleaned all the fuse block connections, replaced the fuse, and checked.

Everything works but with one hitch. With the right turn signal blinking, the dash green indicator does not blink. The left turn signal works and the dash indicator blinks normally. I checked under the dash multi-pin connector, checked both right turn signals themselves, checked the two connectors behind the headlight, ones under the seat, and everywhere else I cound find. Each of those I unplugged and replugged back in. Still, the indicator is usually barely visible with the right signal and fine with the left. All other functions are fine (horn, brake light, etc.).

I can't help but think this is somehow related. Something in the right signal circuit may have blown the fuse. I rode the bike two days before and all was working fine including the dash light. Does anyone have an explanation or suggestion as to what I can check.

Also, battery is fine and ground and hot connections were good and tight. Appreciate any help.

One further update. The dash indicator blinked dimly at first, but doesn't blink at all now although the front and rear turn lights work. I have a shop manual and studied the schematic. I've ruled out the dash connector or the indicator socket as there are only two wires and they work fine on left turn. It is still working normal on a left turn.

I'm thinking the problem would have to be in the turn switch itself or the blinker unit under the tank. I can't figure out how the indicator bulb gets it's hot/ground. The schematic shows one lead to the indicator tied to the right signal bulbs hot and the other to the left hot. Somehow a negative has to get to it. Does the switch ground out the opposite wire which you change left and right? If so, the switch could be the problem. At this point I need someone more knowledgable on how this is wired. If that's how it works, I could try going into the switch housing and clean contacts.

That's a bit weird. You say that both the right & left turn signals are working fine, but the dash light only works for the left?

You're right, the dash light does need to get an earth from somewhere... it gets it by earthing THROUGH the turn signals that are not active. This leads me to suspect that there's a problem somewhere in the earthing of at least one of the right hand turn signals, though how this could be and still have the right hand turn signals working ok is confusing. I think that's why the dash light flashed dimly at first then stopped, as the earth was getting progressively worse (maybe from water incursion, corrosion developping, a wire fracturing, or something working itself loose). Switch on the turn signals, and take & replace out each globe - one at a time - see if anything changes. That may get you closer to finding your problem.

The indicator lamp sources the left lamp for a ground when the right is flashing so I'd start there and work my way back. I'd bet on corrosion somewhere in that path or a chafed wire between the left handlebar control and the headlamp bucket...

I did pull all the right bulbs and check but I didn't pull the left or check it's signal connection. I'll do that. It seems it would have to be the earth (ground) that's getting lost (to the dash indicator) when selecting the right signal, but I can't rule out the right hot either.

Where does the indicator's ground get selected from? From the switch or flashing unit? Somewhere the opposite signal must be switched to ground as the wiring shows both hots going to the indicator.

I just finished pulling the left front signal and signal switching unit. I couldn't find anything that appeared wrong and followed the connections to the headlight multi-pin connector. Studying the schematic again, I can't see how it could be the flashing unit as it only has one connection to the switch. It would have to be something from the switch to the indicator light (or not hot/ground to that side of the switch). I still can't figure out how the hot AND ground get to the bulb. If one of the leads to the bulb were bad (mult or bulb socket) the left signal would not indicate. This has really got me baffled.

The indicator works using the opposing lamp as the ground source, it looks for the left lamp for earth when the right is flashing and vice versa. It took me more than a few minutes to figure that out when I replaced my indicator with a single LED, now I've got a pair of properly polarized LEDs in the indicator housing.

Ed, I had replaced all the indicator lights with the brighter LEDs from Brent. They have been working fine for well over a year. How does the indicator light get the lead switched from left hot to ground? Is this done by the turn switch?

There's got to be someone that would know where to look. I assume it's ok to ride the way it is. Just can't figure out why the indicator won't work on right signal. I haven't pulled the tank and looked at the flashing unit. That's about the only thing left I can think to check. I wish there was a better wiring diagram than the shop manual.

I've been studying that chart and the more detailed wiring chart, but still can't figure out where the problem is. The left bulb to the switch meters good, the input from the flashing unit to the switch has to be good. I took the switch apart. An orange lead from the flashing unit is split in the middle of the switch. There is continuity between them.

The switch shorts this to either the a lead of the left bulbs or right when you slide it. I can't follow the gray wire from the switch all the way to a right bulb but it is joined at a buss somewhere to the indicator. Since front and rear bulbs are working. Where am I losing the connection to the indicator? The wiring diagram doesn't show you exactly where this buss combining point is. I've check all mults and bulb connections. I pulled out the indicator LED and reseated. It has to be getting a good connection through the mult under the dash for either left OR right to work. What am I missing?

Can you put the old indicator lamp back in to see if it's the LED?

Okay, this is how I'm reading it

Each individual bulb has its own ground
The ground for the dash bulb runs through the opposite bulbs to those in use
How I see it is that the indicators would work without the dash bulb being there

Bob, you say that you've got an LED in the dash, which being a diode would only allow the current to flow one way, which rather neatly describes your problem, if I'm reading your posts right

However, you also say that everything was fine for about 2 years, until the fuse blew.
My thought is that your LED might have been a pair built into one lense, which would allow the current to flow both ways through one or the other diode, and the one that lights up when indicating right has failed, probably taking the fuse with it

So my suggestion is to try replacing the LED, or to try my theory, turn the one you've got around, if it'll fit in the holder that way, and see if the fault moves to the left indicators

HTH

Thanks for the input. Yes, it worked fine for a year or more. The LED replacements were designed as replacements and are actually a cluster of small LEDs in each bulb unit. I took it out, cleaned the connections are put it back - not sure if I turned it around. It can go either way. I can try that and will try one of the original bulbs when I have it apart. The bulb does work fine when indicating the left signal. All turn lights work and have good connections to ground.

So, as I understand it now. The dash indicator bulb is actually getting it's ground through the elements of the two turn signal bulbs. I did notice the dash indicator does blink VERY dimly. You have to cup the light to see it. Sure seems like a ground problem.

I'll try replacing and turning around and post the results. I've completely run out of things to try. Don't know why I didn't try another bulb one of the three or four times I've have the dash apart in the last 24 hrs.

Ed and Bryn, thank you for taking the time to help me figure this out. The bike is fixed. Even though I've replaced LEDs in electronic equipment for many years and knew they only worked one way, it slipped by me this time due to the design of these replacement bulbs. They are the LED replacement kit Brent sells and I do recommend them highly. Apparently, although all the LEDs in the cluster work they must be double units and can be installed either way. Didn't even think about it at the time.

I first replaced the original bulb and it worked. I then tried the LED turned around and yes, it did switch sides. I love these much brighter units so I stole the one from the neutral, put it in the turn location, and put the bad one (turned the correct way) back in the neutral. Everything works fine. If it happens again, I'll steal the one from the ignition light. The kit only comes with 3 as you don't want a very bright high beam indicator at night.

You wouldn't believe the time I spent tearing the bike apart and metering connections. Just glad it's fixed. I also realized (having never blown a fuse in 5 years) that there's at least 2 extra 10 amp fuses I can "borrow" in case of failure. The optional accessory socket and the alarm system - both of which are not installed on my bike.

Now if I just hadn't been so impatient to find the problem and given this forum the time to do it's thing, I would have saved a lot of headache.