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Keep blowing a fuel pump fuse???

Posted: Wed Jan 08, 2014 8:18 pm
by Big Daddy Norton
I have a question for the community... I have a 02' R1150R non-ABS that I have up-graded with some new features, installed an HID head light (Bikemaster H4), new louder horn (Wolo w/20 amp inline fuse) and an LED tail light. The head light works great, the horn is ear bleedingly loud and the tail light is now extra bright. I put the horn in the area where the ABS stuff nomaly would go. I have every thing grounded to the metal frame (head light and horn) and other than removing the fuel tank to access my battery that's all I've done. I put everything back per the service manual instructions and when I crank the bike it runs beautiful for 60 seconds and then pops the fuel pump fuse. I took everything back apart to check and see if I had any exposed wires and I couldn't find any, I unhooked all my additions and still it will pop the fuse in 60 seconds. I even made sure the fuel lines weren't pinched, but I can't seem to understand why the bike is popping this one fuse in a 60 second period. 5 fuses later can someone offer an explanation?

btw... I didn't have any 4.5 amp fuses so I have been using 5 amp fuses for the fuel pump.

Thank you,
Walter

Re: Keep blowing a fuel pump fuse???

Posted: Wed Jan 08, 2014 9:30 pm
by AZBMWRIDER
Try disconnecting the electrical connector on the right side of the tank for the fuel pump, turn the key to the 'ON' position for a couple of minutes and see if you still have the fuse melt problem .
Eliminate the fuel pump as a cause .
Only cause I can think of now, is a possibility of a wire with a chaffed area or cut insulation that is touching a ground .

Re: Keep blowing a fuel pump fuse???

Posted: Thu Jan 09, 2014 8:26 am
by towerworker
Another member recently posted that after doing some work on his bike that it would not start. Ultimately found a fuel line inside the tank shook loose. Bad clamp it seems. I wouldn't suspect that in your case but stranger things have happened. If one came loose it wouldn't start. Have you checked the tank for a vacuum? If a vent line were pinched it would cause a vacuum which would put a load on the pump and ultimately cause the pump fuse to blow.

Re: Keep blowing a fuel pump fuse???

Posted: Thu Jan 09, 2014 12:01 pm
by kirby
Before you did all your mods the fuze was not blowing? Usually when something like this happens AFTER you do some mods it points to something you have done as the cause.
I will look at my diagrams (electrical) and see what else is on that circut later today.

BTW How many miles? Ever changed the fuel filter?

mike
EDIT:
I just checked my clymer manual and it shows the #6 fuze is the fuel pump. I checked my bike and this is correct.
Possible fix,
The clymer manual lists this fuze(#6) should be 10 amps. I checked mine and it is indeed 10 amps. If your blowing # 6 and it has a 5 amp that could be the problem. (Count left to right facing forward should be 7 fuzes on you machine)

cheers
mike

Re: Keep blowing a fuel pump fuse???

Posted: Thu Jan 09, 2014 1:47 pm
by eduardobelmonte
The wiring that leads to the pump probably has a shortcut.
If you do disconnect the connector located below the tank, and you still have a blown fuse, then that means the shorcut is before the connector.
If you do not get a blown fuse with the connector disconnected, that means the shortcut is between the connector and the pump itself.
If this last case you get, then the problem may be on the wiring or on the pump itself.
So check the wiring ....
I cannot tell if the pump itself is/ would be able to generate a shortcut by ITSELF.

I can tell though that just moving the tank made the hose that connect to the pump to be disconnected. (inside the tank). This didn't damage anything, but the bike had no supply so it would not start.

Do you hear the pump when you switch the bike on? That means the pump is working.
When I got the hose disconnected, I didn't hear the pump working. I had no blown fuse in any of this ordeal, it just didn't sound at all. When I reconnected the hose (inside the tank) no other mod done, every thing worked correctly.

Also you can measure and see if there is voltage at the connector when you switch the bike on.
The brown cable is negative.

Re: Keep blowing a fuel pump fuse???

Posted: Sun Jan 12, 2014 4:55 pm
by Big Daddy Norton
Thanks to all the folks that replied!!! And the winning answer was.... kirby! You were correct the fuse was supposed to be a 10 amp and not a 4.5 amp like I had thought, my bike runs like a dream now. I think what threw me was the strange looking fuse that this bike has, I'm not sure if they were BMW original but they were not like any fuse I had seen before.

Thanks again to AZBMWRIDER, towerworker, kriby, eduradobelmonte for all the excellent advice.

Walter

Re: Keep blowing a fuel pump fuse???

Posted: Sun Jan 12, 2014 5:00 pm
by kirby
Your very welcome, happy that it was a simple fix!
cheers,
mike

Re: Keep blowing a fuel pump fuse???

Posted: Sun Jan 12, 2014 6:29 pm
by AZBMWRIDER
You just can't never tell where troubleshooting will lead you .
Aren't previous owners a ' wonderful ' thing at times ????? :badgrin: =D> [-X
Glad to hear it was a ' simple ' fix, well at least not costly !!!