Problem on my motorcycle.

I have been blowing fuses on the circuit for the Taillight/turn signals/dash lights on the Ducati. I have since narrowed it down to the left handlebar control. This control has the turn signal switch/high low beams/passing light(high beam blinker)/horn.

If I unplug the entire harness for the control, the fuse does not blow. I tried splicing each wire so I can plug/unplug each wire one by one to see which one is bad. This didn't work. Even if all the wires are disconnected as soon as I plug the harness in (cut wires at the other end) it will blow the fuse. Is the connector bad? I am stumped.

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'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

vwbuge:

Look carefully at the area of the harness from the point where it exits the handlebars all the way to where the harness meets the frame.

Look for worn insulation, wiring that's "bunched up" or twisted, and carefully check each wire for tears or cracked insulation the could lead to exposed strands of wire within the wire itself.

NEXT: Isolate the wiring harness from the loads - i.e.: remove the turn-signal bulbs, the head-light, the blinker for the head-light and the horn.

Plug in the harness. No blown fuse? Then start manipulating the controls for those loads - i.e.: Work the turn-signal switch, the HI/LO Beam switch, the Passing switch and the Horn button/switch. Still no blown fuse?

NOW, add the loads, one at a time and operate the associated switch, and while you're working the switch, work the steering back and forth to be sure the harness isn't still involved.

Somewhere along the line, you're going to get your blown fuse.

THEN, you've nailed it down and you're on your way to getting the problem FINALLY FIXED.

Good luck and remember, document each step you're performing - you don't want to miss, or skip, anything.

Trouble-shooting electrical problems is one of the hardest disciplines to learn, but if done right, is VERY rewarding.

__________________

M. G. Burg
'10 - Dakota SXT - Daily Ride / ≈ 172.5K
.'76 - 450SLC - 107.024.12 / < .89.20 K
..'77 - 280E - 123.033.12 / > 128.20 K
...'67 - El Camino - 283ci / > 207.00 K
....'75 - Yamaha - 650XS / < 21.00 K
.....'87 - G20 Sportvan / > 206.00 K
......'85 - 4WINNS 160 I.O. / 140hp
.......'74 - Honda CT70 / Real 125
.
“I didn’t really say everything I said.”
. . . . . . . . . . . . . . . . . . ~ Yogi Berra ~

Been there, done that so to speak. I unplugged the entire dash cluster. Still blows fuses. I unplugged the front and rear turn signals, still blows the fuse. I am now leaning toward the headlight. I don't think the headlight has anything to do with it. It is always on and is not associated with the fuse that blows. BUT, the high beam blinker is on the control.

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

Either way, removing the load(s) will help isolate the path that the problem is following...but take care and check any area where the harness is flexing.

One of the worst problems to track is an intermitent, and if it's in a wire bundle, God help you and your patience...

But, isolate the HBBlinker and the H/LBeam bulb and see if you're still blowing the fuse.

If not, YOU'RE GETTING CLOSE!

__________________

M. G. Burg
'10 - Dakota SXT - Daily Ride / ≈ 172.5K
.'76 - 450SLC - 107.024.12 / < .89.20 K
..'77 - 280E - 123.033.12 / > 128.20 K
...'67 - El Camino - 283ci / > 207.00 K
....'75 - Yamaha - 650XS / < 21.00 K
.....'87 - G20 Sportvan / > 206.00 K
......'85 - 4WINNS 160 I.O. / 140hp
.......'74 - Honda CT70 / Real 125
.
“I didn’t really say everything I said.”
. . . . . . . . . . . . . . . . . . ~ Yogi Berra ~

Keep the thoughts coming. I have a little more time to type now.

Right now the instrument cluster is plugged in and all the lights work on it. The tail light also works. The handle bar control is unplugged. Everything is fine and the fuse doesn't blow.

As soon as I plug in the handlebar control it will blow the fuse when the ignition is turned on. I took apart the control and traced each wire. None seem to be kinked bad or worn. They also seem to be secure at each end. I also put a new end terminal on the ground wire. I also went as far as to cut each wire and put disconnect terminals on them so I could pull them one by one to diagnose. With ALL the wires disconnected at my quick disconnect terminals (except the ground) I plugged in the main handlebar control harness and tried it. It will still blow the fuse with ALL the wires disconnected!?!?!?!

Do you think the short is in the harness connections?

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

since when did ducati's use lucas electronics???

That is not funny........I also have a '72 Triumph......well, I guess it was kind of funny.

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

One thing I saw on a '77 Yammie once (no comparason, I know....)

The solder joint that attached a wire to one of the contacts inside the switch cluster was distorted and was touching the handlebar when you attached the switch cluster to the handlebar itself - this blew the fuse and left a little (little...) burn mark on the handlebar itself (which was chrome - made it easier to notice)

something to keep an eye out for.

-John

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2009 Kia Sedona
2009 Honda Odyssey EX-L
12006 Jetta Pumpe Duse
(insert Mercedes here)

Husband, Father, sometimes friend =)

I got the replacement handlebar control today. I connected everything and all is well. Or should I say WAS well. Everything worked great. I tried all the turnsignals and lights, everything was cool. I started her up and let it idle for a minute or two. Shut off the choke, revved it up a few times and BLEW THE F$^%#&N fuse again!!?!?!?!?!?!

Is there a possiblitiy of the voltage regulator being bad and blowing just this ONE circuit?

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R