I have a 2000 750 monster that has spent sometime in pieces. It is all back together by I am having an issue with the 7.5 amp fuse that supplies the neutral switch, oil pressure swith, side stand switch and I think the turn signals blowing as soon as I turn the key to on.  I have disconnected all switches and I have checked continuity and all is well.  Could this problem actually be on the incomming side of the fuse ie.... the power comming in.   If it could I would imagine that it wouldnt be a short but maybe a power supply malfunctioning.

Are there any other wiring schematics out other than the one that is in the owners manual?

E.

Check the turn signal wires, especially if you don't have the rear signals hooks up.  If these touch each other or short to ground, your gonna blow that fuse.  Happened to me when I put my bike back together. 

Good call.  I do remember having issues with hooking the rear signals up.  Let you know what happens....

E.

IIRC the fuse for the lighting is supposed to be 15 amps.

The only 7.5 fuse in my bike is for the ignition.

The only way that loose turn signal wires will blow the fuse is if the turn signal is turned on.

Cancel the turn signal switch and if it still blows the fuse when you turn the ignition on, the problem is something else.

If the fuse doesn't blow after canceling the switch, that's the problem.

Quote from: ducpainter on August 10, 2008, 08:03:19 PM
IIRC the fuse for the lighting is supposed to be 15 amps.

The only 7.5 fuse in my bike is for the ignition.

I definitely have another 7.5 amp fuse on mine.  Pretty sure it is the signals because when I blew it I only had a 15 and stuck that in there for a while until I could get another 7.5.

Quote from: Rameses on August 10, 2008, 08:42:12 PM
The only way that loose turn signal wires will blow the fuse is if the turn signal is turned on.

Cancel the turn signal switch and if it still blows the fuse when you turn the ignition on, the problem is something else.

If the fuse doesn't blow after canceling the switch, that's the problem.

Good call unless one is some how touching a live wire.

Quote from: Jobu on August 10, 2008, 10:50:25 PM

Good call unless one is some how touching a live wire.

In that case if it were the ground, it wouldn't blow the turn signal fuse, it'd blow the fuse for whatever the live wire was that was coming into contact with it.

If the turn signal hot wire were coming into contact with another hot wire, nothing would happen.

Shorts or high amp draws blow fuses.  Since the circuit you are dealing with doesn't have anything on it to cause a high draw you are dealing with s short, probably a short to ground.  The problem will be after the fuse.  Unfortunately, there is no easy answer.  Finding the cause is a process of elimination.  Start with what Rameses suggests.  If the short is between a switch and a bulb the fuse will not blow until that bulb is activated.  If the fuse blows immediately the short is before the switch.  A wiring diagram will be quite helpful.  A diagram is in the back of the owner's manual and is available here:   http://www.ducati.com/en/bikes/service/manuals/2000.jhtml?family=manuals

The fuse is supposed to be 7.5 amps.

An aid to finding shorts is to plug in a circuit breaker with the same rating as the fuse.  The breaker will keep tripping, protecting the circuit.  Each time the breaker resets it will allow current to flow.  each time it trips current will stop.  With an inductive ammeter follow each circuit.  The point just before the pulsed flow of current stops is where your short is.

You can add 2 more fuses to my count. I am getting closer though.  After unplugging the wiring harness that supplies the left side of the handle bar, I found that the fuse does not pop.  When I connected it back up it popped.  I disassembled the switch housing and tested all connections and all was good.  This evening I am going to check from the switches to the turn signals.

I am not sure how I am getting a short since the turn signals are not switched on. 

E.

I would strongly recommend AGAINST putting in a larger fuse.  That can lead to melted wires.  I'm embarrassed to admit that I know this from personal experience.    

Quote from: MonsterAD on August 12, 2008, 01:32:44 PM
You can add 2 more fuses to my count. I am getting closer though.  After unplugging the wiring harness that supplies the left side of the handle bar, I found that the fuse does not pop.  When I connected it back up it popped.  I disassembled the switch housing and tested all connections and all was good.  This evening I am going to check from the switches to the turn signals.

I am not sure how I am getting a short since the turn signals are not switched on. 

E.

Sounds like you are headed in the right direction.  My guess is something in the switch is broken and leading to ground.

Sounds like you are on the right track here.  One trick that works pretty well for locating dead shorts is to get creative with a bulb and solder 2 leads onto it with blade connectors on them.  plug the two blades into the ports for the fuse and if you have a short the bulb will light up.  When you eliminate the short the bulb will shut off.  You can't damage any wiring that way, it makes it pretty obvious if the short is still there or not, and you won't go through a pile of fuses.

Quote from: JohnnyCanuck on August 12, 2008, 08:31:30 PM
Sounds like you are on the right track here.  One trick that works pretty well for locating dead shorts is to get creative with a bulb and solder 2 leads onto it with blade connectors on them.  plug the two blades into the ports for the fuse and if you have a short the bulb will light up.  When you eliminate the short the bulb will shut off.  You can't damage any wiring that way, it makes it pretty obvious if the short is still there or not, and you won't go through a pile of fuses.

Holy shit, that's a really good idea.

I kinda feel dumb for not thinking of that.   

Thanks for the great Idea. Makes me wonder why I never thought of that. I guess I will try it tonite.


E.

Before last night, I had looked at the wiring diagram a hundred times, and it wasnt until last night that I noticed that the license plate light was also part of the circuit and my problem.  It all makes sense now because that part of the circuit is always "hot," and a short there would most definitely burn 8 or so fuses.  Sorry to bother everyone with this, but thanks for all of the ideas.

E.