Electric short

[Bugtarget]

Hi All!

When I turn the ignition key on the F5 15amp fuse immediately melts. This controls the headlight, horns, etc. Any tips on a place to start or a common issue in this circuit. Thanks for any help!

2002 V11 LeMans

[docc]

Try removing first the tail light bulb, then the headlight bulb. They're easy to get to and could fault the circuit.

 

Second, see what happens with the second relay removed, then swapped for an spare.

 

Has anything been apart and back together on the bike lately?

[luhbo]

..and stop feeding fuses to the short. To better your chances for finding the short solder a 12V rear light bulb to an old fuse (or similar) und plug this in. (was one of the better ideas I could pick up here )

[Chuck]

^^^^^ Shorts are easy to find that way. As Docc sez, though.. it may be nothing more than a bulb.

[Kiwi_Roy]

I don't think it will be in the tail light, that's fuse 6

Unless it's in the stop light but that wouldn't blow until the brake is applied.

More likely to be in the idiot lights , you haven't replaced any of those bulbs have you? Some lamps short out the holders because the wire touches both contacts.

 

I have always advocated using type 194 LEDs without a holder

 

Yes, a lamp in place of the fuse is the best method of finding a short, I use an old headlamp bulb with a couple of wires soldered on, it can supply more current to liven up the circuit normally.

It flashes at you every time you create the short.

[docc]

Thanks, gentlemen. Entirely true about the tail light (doh- I knew that!)...

 

Consider visually inspecting the wiring harness along the frame where you can see it along the frame for any signs of melting or rodent damage.

[Kiwi_Roy]

My monies on the Idiot lights

 

Bugtarget, you can narrow it down a bit by unplugging the different connectors then putting them back one at a time.

This Schematic is close enough

http://www.thisoldtractor.com/guzzi007/schematics/2004_V11_Sport_Catalytic.gif

 

Unplug the headlight relay (34), i'm pretty sure that will clear the fault

 

With the relay back in

See the Red/Black wire going to connector (8) unplugging it will disconnect the idiot lights

 

The Red /Black wire also goes the the LH dimmer switch and the two brake switches.

 

It also went to the Voltage regulator on earlier models.

 

Those idiot light sockets are crap, some lamps short them out, I always throw them away and install 12V LEDs

[Bugtarget]

Thanks for the suggestions! I now have renewed motivation and will go out and try the headlight and idiot bulbs.

[Bugtarget]

My monies on the Idiot lights

 

Bugtarget, you can narrow it down a bit by unplugging the different connectors then putting them back one at a time.

This Schematic is close enough

http://www.thisoldtractor.com/guzzi007/schematics/2004_V11_Sport_Catalytic.gif

 

Unplug the headlight relay (34), i'm pretty sure that will clear the fault

 

With the relay back in

See the Red/Black wire going to connector (8) unplugging it will disconnect the idiot lights

 

The Red /Black wire also goes the the LH dimmer switch and the two brake switches.

 

It also went to the Voltage regulator on earlier models.

 

Those idiot light sockets are crap, some lamps short them out, I always throw them away and install 12V LEDs

I first noticed the problem when the bike was running and I hit the horn button. The fuse popped then. I hadn't ridden the bike in a while and thought I'd be okay for a spin through the neighborhood. Well, a half mile from the house and the reg/rec started smoking. I pushed the bike home. Replaced the reg/rec and the bike runs great but the problem remains with the blown fuse.

[luhbo]

You should try to get some professional hands-on help at this point. Don't ruin the cable harness, else you probably will have to sell your bike for cheap.

[Bugtarget]

UPDATE-

Took the dash apart to get to the idiot bulbs but all LOOKS okay. But, I found out that the #5 fuse doesn't pop when the #1 relay is removed but the #2 relay stays in place. Not being a sparky, does this help in isolating the problem?

[docc]

What about pulling Relay2 or replacing it with a spare?

 

Did you inspect the headlamp bulb or pull it and see if the fuse still blows?

[Bbennett]

BTW Bugtarget, as you probably know, there are some excellent Guzzi repair pros in Seattle, send me a message if you want me to point you to some (no affiliation to me).