Fuel pump fuse blowing/short

[DucriderTroy]

I have a 2001 Monster 900Sie. I have a problem with the 20amp fuel pump fuse blowing. I had it go out after riding up a bumpy gravel drive to my place. Once I found the blown fuse, I replaced it and it blew instantly. If I keep the tank propped up, the pump primes and the engine fires right up. As soon as I lower the tank and the clamp hook touches the mounting flange to the frame to cinch it down, it blows the fuse again. I saw a small spark where it touched. There is obviously a short somewhere. My question is if the short could be in the 4 wires gong through the fuel level sensor with 2 of those continuing to the pump. Over a year ago I had a wire break in the harness that wraps around the steering head. Turning the bars left to lock the steering pulls on those wires. The engine would cut out. I don't feel this would be contributing to this current issue because that was wires disconnecting, not touching and causing a short. I'm hoping someone has has a similar issue and will be able to let me know where the issue was found and how it was repaired. The pump and other internal tank components look in great condition.

Thanks in advance!

[koko64]

Yes, and as you know those wires are notorious for failing, you most likely need to repair those again or the loom connection to them. Since the short is significant and relates to the fuel system, Respect The Fuse!  The repair job has failed over time or a major replacement is required. The tank latch spark is a warning! Unless your diagnostic skills enable you to confidently and safely refit a fuse and diagnose the issue I would pay a licenced, insured sparky. This isn't a shorting, low amp turn signal, the tank latch attached to a steel fuel cell is 20 amp live and shorts to the frame when latched down! The fuse has done its job.
It is a great model 900 and worth having a licenced auto sparky check it out.

The 900ie has double the airbox capacity and hotter cams than the carb model with no carb freezing. You can add high compression pistons without the need for ignition changes or heavier engine studs. Using premium fuel, a remap and open airbox gives a torquey lightweight bike that does 3rd gear wheelies. A great model.

[Howie]

Short to ground.  Closing the clamp is completing the circuit.  If you decide to work on the bike yourself I suggest you remove the suspect component from the tank and diagnose by eye and ohmmeter.  Sparks and gasoline.  I agree with koko64 about  getting the bike to pro if you are not confident in your skills.  Koko, this is the US where anybody can say I are a auto mekanik

[DucriderTroy]

Thanks for the replies. I have already pulled the pump with filter and fuel level sensor out of the tank. I've seen posts about the epoxy seals in the pumps turning to mush, but my pump looks nearly new and operates as it should with the tank up. I assume there is not enough continuity between the tank and the frame where it is hinged or it would have blown the fuse regardless. This is why I suspect the fuel level sensor. I'm going to see if I can determine an issue with it by checking the continuity with the ohm meter. I don't mind spending the money for a replacement if I'm confident that is the issue. I just don't want t waste the money either.

The local motorcycle service center are not good in my area. The shop that found the broken wire issue had my bike for months. I had to keep hounding them after a while to get them motivated to work on it. Then they managed to crack the seat cowling because they pushed down on it to remount the seat. I should have removed it before leaving it with them, but...

It has K&N air filter and Termi exhaust. Sounds incredible and has surprising power for an air cooled 2-valve twin. I'm itching to get it back on the road before it gets too cold to ride this year. I will have owned this bike for 20 years next month. It's fun!