Fixing a fuel pump short on my Ducati Monster 900Sie

[0ldp!70t]

I am dealing with a frustrating electrical short on my 2001 Monster after riding on a bumpy road. My twenty amp fuel pump fuse keeps blowing the second I try to latch the tank back onto the frame. The bike runs perfectly fine when the tank is propped up but I see a spark as soon as the mounting hook touches the metal flange. It seems clear that a wire is getting pinched or has lost its insulation somewhere near the fuel sensor and pump harness. I suspect the wires running through the bottom of the tank are the main problem area. And I am looking for advice from anyone who has tracked down a similar short in this specific spot. I want to fix this without tearing the whole harness apart if possible.

 

[g0alkeeper]

Have you looked for any exposed copper on the four wires where they exit the tank flange?

 

[1000spaghetti]

I want to fix this without tearing the whole harness apart if possible.

check the 4 pin connector near the rear of the tank. the insulation usually cracks right where the wires exit the fuel pump assembly
if you're seeing a spark at the mounting hook, the pump's positive lead is definitely grounding out through the tank body. try wrapping the subharness in Rescue Tape, it’s thinner than electrical tape and handles the heat/rubbing much better

 

[lavend3r]

You should try wrapping the harness in fresh electrical tape or a rubber sleeve to prevent it from grounding against the frame.

 

[uglytruth]

I am dealing with a frustrating electrical short on my 2001 Monster after riding on a bumpy road. My twenty amp fuel pump fuse keeps blowing the second I try to latch the tank back onto the frame. The bike runs perfectly fine when the tank is propped up but I see a spark as soon as the mounting hook touches the metal flange. It seems clear that a wire is getting pinched or has lost its insulation somewhere near the fuel sensor and pump harness. I suspect the wires running through the bottom of the tank are the main problem area. And I am looking for advice from anyone who has tracked down a similar short in this specific spot. I want to fix this without tearing the whole harness apart if possible.

Have you tried using a multimeter to check for continuity between the fuel pump power wire and the tank body while it is raised?

 

[kwyatt01]

@0ldp!70t Does the fuse still blow if you disconnect the fuel pump electrical connector before lowering the tank?

 

[Alan]

Well, since the short only occurs when the tank is lowered, I think you have a wire in the fuel pump or sensor harness that has rubbed through its insulation and is grounding out against the frame rail or the mounting flange. Try to check that first.

 

[explorer]

@0ldp!70t You should look for any rub marks on the frame itself where the wires might be resting when the tank is in the down position.

 

[0ldp!70t]

Well, since the short only occurs when the tank is lowered, I think you have a wire in the fuel pump or sensor harness that has rubbed through its insulation and is grounding out against the frame rail or the mounting flange. Try to check that first.

You are right! That is the culprit. My buddy offered to repair it this weekend, and he has also secured all the things he needs to fix it.

 

[icec0ld]

Rerouting the harness a bit helps. So that it has extra slack once the mounting hook is clipped in.