Turn & Hazard fuse failure

[T120TT]

My 2006 AE suddenly developed a problem. It immediately blows the 10 amp turn signal fuse anytime I try to use the turn or hazard signals. Also, when the fuse blows with the engine running, the engine exhibits an instantaneous slight stumble as the fuse blows. The problem appeared suddenly regardless of whether the engine is running or not. I haven't made any recent mods. When I disconnected the turn signal relay, the fuse stopped blowing. Could a defective turn/hazard signal relay cause this? Seems highly improbable to me. The bike has only 8500 miles. All the factory recalls have been done {ignition switch, high altitude ECM, S4 spider ground jumper harness} long ago. No spiders appear defective, but I removed the S6 spider and soldered together as a preventative measure after the fuse blowing problem began. I've had highway blaster horns installed for several years. The bike starts and runs normally except for the engine stumble {very slight} The gages work fine as do the lights, except for the turn/flasher signals, of course. No codes. Problem not correlated with any recent mods. Any ideas? Thanks.

 

[Uncle Hud]

Others will have more substantive responses, but the fuse blows because of over-current faults. That means something's shorting to ground: relay, bulb or socket, connector in wiring to turn signals or hazards. (I assume you had whatever work was required under the ground spider recall?)

The stone-age troubleshooter (me) would remove all the removable items in the circuit, replace the fuse, then add the removables back one at a time. When the fuse blows, you'll have identified the bad component.

 

[SLK50]

I think only moving 850 miles a year may have something

to do with it?

One of my bikes had a turn signal relay that wasn't sealed.

15 years of rust and corrosion did it in. I'd try a new one.

 

[mcatrophy]

The engine stumbles because you've got a short circuit until the fuse blows, so the ignition voltage disappears.

It's unlikely to be the turn signal relay. My reasoning is that power comes from the hazard light fuse, always through the turn signal relay*, and then feeds the turn switch and the hazard switch, so this line is powered whenever the ignition is on.

It's got to be a short after the switches.

Does it blow the fuse with the turn switch in both directions, or only one? I would be very surprised if it was both.

Check the wiring loom, particularly from the switches down past the ignition switch, look for any fretting. The other likely problem area would be under the seat, where the loom could be snagged.

You can unplug the rear lights and the individual front indicators, can't remember how accessible these connectors are.

If you can unplug/remove all the bulbs, there should be no current draw even with the switches on. You could use a 12 volt bulb connected (with suitable wires) instead of the fuse to indicate current flow.

If you are really lucky, it'll be a bulb, though I've never heard of an automotive bulb failing short circuit.

[edit] - sketch of the indicator circuit:

[/edit]

* The term "relay" is something of a misnomer, it's an interrupter, probably working by the current heating a bi-metallic strip. When it gets hot enough, it bends and breaks the electrical circuit. With the current interrupted, it cools, relaxes, and makes connection again.

 

[Uncle Hud]

^^^^ True about bulbs shorting to ground -- since they normally connect to ground and glow from the electrons flowing through their filaments. Electrons and filaments are hot couples. (<---- Didn't come out as naughty as I'd hoped.)

Erm, just as shown in mcatrophy's very helpful sketch.

 

[Donal]

Occasionally bulbs can fail and cause a 'short' to ground. This usually happens when the filament ruptures and then 'reconnects' but much shorter than before. This shorter filament causes a serious increase in current flow. Usually the shorter filament will rupture (taking the fuse with it) just one time, but.................

Recommend you remove all four indicator bulbs and see if that corrects the problem.

If it does then either check the bulbs with a Multi Meter or just try them one at a time.

 

[T120TT]

It blows the fuse with all the turn signal lights disconnected and in either direction, left or right. I sacrificed two more fuses just to make sure. Hmmmmm.... I REALLY don't want to take it to a dealer unless it's D & H Cycle in Cullman, AL, but that's an eight hour drive from here.

 

[T120TT]

I removed the turn signal relay and jumped the two wires leading to the relay, then tried the turn signals again. Same result; blown fuse. Not sure what this may mean.

 

[wfooshee]

It means that somewhere along that wire is a cut or some other piercing of the insulation allowing the wire to touch a metal ground.

Bulbs in or out doesn't make a difference because the short is still a circuit. Removing the bulbs doesn't make the wire "dead" if it's shorted to ground, nor does removing bulbs one at a time identify which wire it might be.

Removing the bulbs tells you that it's along a wire between the fuse and the lamp socket. Which you pretty much already knew, since after the bulb IS the ground, and it's pretty hard to short there, and before the fuse..... won't blow the fuse.

I know I'm being just a bit sarcastic and perhaps unhelpful, but that's because there's no help to give, really. You've got a wire cut somewhere allowing a 12-volt load to touch a ground. If you pull all the bulbs and the fuse and put an ohmmeter lead in the circuit-side of the relay socket and the other lead on a ground, you'll get a very small number of ohms. Again, no help, you already know it's shorted. Somewhere.

Actual guidance begins here: I'm not sure what you can do other than examine the wiring harness. I've seen the harness get pinched along the sides under the tank, but under the seat is another possibility. Look for places where the tape wrapping the harness has been abraded. You might have a bolt or something punched through the harness and eventually into a wire.

 

[Donal]

It blows the fuse with all the turn signal lights disconnected and in either direction, left or right. I sacrificed two more fuses just to make sure. Hmmmmm.... I REALLY don't want to take it to a dealer unless it's D & H Cycle in Cullman, AL, but that's an eight hour drive from here.

There's a definite clue there. What is common to left & right?

Any farkles fitted? It is not unusual for people to fit audible alarms to remind them to cancel the turn signal.

Something like that would be common to both sides.

The only other thing I can think of that's common is the panel indicator.............

 

[mcatrophy]

...

The only other thing I can think of that's common is the panel indicator.............

Nope, there are two separate indicators on the panel, so not common (added to my diagram above).

 

[T120TT]

I had a couple sound buzzers {piazo buttons?} from RadioShack inserted into the rear signal connector and a pair of Highway Blaster horns and a Power Commander and the S4 jumper ground installed by the dealer. All have been installed for quite some time. I disconnected the signal buzzers but it made no difference. I may have to remove the front cowing tupperware to get a good look. I had the ignition switch update done by the dealer as well. Also installed bar risers witch may have stretched the wiring. BTW, it really pays to belong to this board. Thanks for all the help, guys. All comments appreciated. I'll let you know what I find. After all, it's got to be something! LOL.

 

[wfooshee]

I still think it's going to be under the tank or the seat. That's where the wiring harnesses run right along the frame, squeezing through narrow spaces and past fasteners.

 

[Donal]

Don't forget - you are looking for something that is common to both sides. Mcatrophy's diagram above should be your guide.

It could be that you have developed a fault on each side simultaneously, but what are the chances of that.

Places that both sides come together are at the switches.

Might be worth opening the switches on each side and have a look see..................

 

[mcatrophy]

...I sacrificed two more fuses just to make sure....

That's why I suggest a light bulb connected where the fuse goes.

I don't really understand how it can be both sides at once, unless something fairly catastrophic has happened to the wiring somewhere.

 

[T120TT]

Whatever is the cause, it's confined to the signals and hazard circuit. Obviously, I don't understand it either. I'll open the switches next for a look-see. Stand by....

 

[mcatrophy]

Whatever is the cause, it's confined to the signals and hazard circuit. Obviously, I don't understand it either. I'll open the switches next for a look-see. Stand by....

Very unlikely to be the switches. Neither have any ground wires within them, and they are made of plastic, so nowhere for the electicity to find a path to ground. Having said that, I don't know where the problem is likely to be, and I've not had either of those switches apart, so I suppose there might be a mounting feature that could provide a short to ground. But, both sides?

 

[T120TT]

Exactly. Not the switches. I'm taking a break for the weekend. Stand by...

 

[wfooshee]

You know, I saw that it was turn or hazard, but I completely missed that it was either direction. That would make you think it's in front of the switches (the only wiring in common to both turn and hazard,) but it can't be or the fuse would blow instantly, not just with the turn or hazard.

My 2006 service manual has different colors on those wires. Blue/red from the fuse, Brown/green after the flasher relay, Chocolate for left and Dark green for right. (OK, he said green, I said dark green. Fine. Dark grey is not Chocolate, though. He must be color blind

) The Blue/red wire also supplies voltage to the tail lights, the license plate light, and the front marker lights. Anything on those circuits, like a relay tap or power supply for an accessory will add to the fuse's load, so one might think that something's going on there. Such a situation might not be an indicator of a short, but simply an overload, since those lights are on the same fuse. Removing the lamps and still blowing the fuse makes me think not, though, as without the bulbs there is no added load when the signals get switched on. The bulbs should be the only load.

That puts us back to a shorted wire. Since left or right doesn't matter, it leaves us with both wires shorted to ground. That could easily happen since they both pass through two connectors. I can't tell you where those connectors are, but on my diagram they are labeled 63 and 32. Maybe someone more familiar with Gen II can advise here. Anyway, it looks to me like it has to be on the Dark green and Chocolate wires, which on mcatrophy's diagram are labeled Green and Dark grey.

And that makes under the tank or under the seat still the most likely place for them to get pinched and cut.