Fuel Pump problem

[Balibeemer]

. The bike (2002 1150 RT) turn over but the fuel pump fuse keeps blowing. Any suggestions?

[dirtrider]

2 hours ago, Balibeemer said:

. The bike (2002 1150 RT) turn over but the fuel pump fuse keeps blowing. Any suggestions?

Morning  Balibeemer

 

We need more info & more motorcycle history to give you anything more than just general things to look at.

 

It is probably either a short to ground in the fuel pump circuit or other things on the fuel pump fuse circuit like fuel injectors. 

 

If the motorcycle has been sitting or stored for while then possibly a  seized up pump or a stuck pump impeller. 

 

Are you using the proper sized fuse?

 

Have you tried it with the fuel pump pig tail disconnected from the motorcycle harness, this will tell you if the problem is in the fuel pump itself or in another location. 

 

All the things below are on the 10 amp fuel pump fuse circuit____

 

fuel pump
fuel pump relay
both side fuel injectors
fuel tank breather valve

[Balibeemer]

Thanks for the reply DR. 
The bike was running fine about 3 weeks ago. I had to replace the battery and did so and then did the TPS relearn. After that, the problem of the blown fuse emerged. I have checked for squashed / broken cables but can find none. I have fuel in the bike. The fuel pump does not cycle when turning on the bike. The battery is at full charge and the engine turns over but does not fire. 
That's about it!

[Balibeemer]

Correct fuse. 

[Balibeemer]

.....and the fuel tank indicator (on the RID is not working!

[dirtrider]

7 hours ago, Balibeemer said:

.....and the fuel tank indicator (on the RID is not working!

Morning  Balibeemer

 

Is the neutral light ON and/or the side stand UP? Won't cause the fuse to blow but could cause a starting problem.

 

The RID is on a different circuit, so you have some strange things going on. But the fuel pump plate (pass through) is a common link between the fuel pump & fuel gauge) 

 

Is fuse #5 still good? Check this?

 

Did you do anything else to the motorcycle when installing the new battery, any loose wires at the battery posts that you might have put on the incorrect post?

 

Is it still blowing the #6 fuse? If so then WHEN does it blow?

Right at fuse install?

Or at key-on?

Or at first engine cranking?    

This can tell us something.

 

Also make sure that your o2 sensor pigtail is not hanging down on the exhaust or is pinched.

 

Otherwise, you are probably going to need some 10 amp fuses then start disconnecting things,

 

like fuel pump relay (that pretty well disconnects most on that #6 fuse (if that stops the #6  fuse blowing then reinstall it). If not then stop here & post back with that info. 

 

Then disconnect the fuel pump pigtail connector. Does this stop the #6 fuse blowing (yes or no?)

 

Then disconnect the wires to both fuel injectors.    Does this stop the #6 fuse blowing (yes or no?)

 

Then unplug the o2 sensor pig tail.   Does this stop the #6 fuse blowing (yes or no?)

 

There is a fuel tank breather valve on the L/H side (about mid motorcycle) is that still on the motorcycle? This usually gets removed if the black evap canister was removed (canister removal). If breather valve is still there then try disconnecting it. If it is gone then make sure the wire pigtail isn't pinched or shorted. 

 

Does your motorcycle have anything added to it like a Dobek TFI aftermarket fuel controller? If so then disconnect that from the o2 sensor circuit. 

 

This type of fuse blowing (usually a short to ground) is difficult  to find remotely over the internet as we can't see anything, and can't quickly check circuits, & have to wait for feedback from the poster befor the next move. 

 

You can eventually find it but you have to be persistent & thorough (no guessing). 

 

First thing, you need to find out is: WHAT is causing the fuse to blow, THEN we can address WHY that item is causing the fuse to blow.   

 

 

 

[Balibeemer]

Correct fuse. I'm traveling at the moment and will respond in a couple of days

[Michaelr11]

When I was having a problem with fuse blowing on my airhead, this is what I did.

 

Hook up a turn signal bulb or headlight bulb with a wire pigtail. Remove the fuse that keeps blowing, and connect the two wires for the bulb into the fuse holder, one wire at each side. This will set up the bulb in place of the fuse. If the circuit is on and working, the current will just run through the bulb,. It will either be off or it will glow slightly. As soon as you connect or turn on the problem part, or move the wire that is grounded, the bulb connected to the fuse holder will turn on bright.  This will let you check all of your circuits without continuously replacing fuses.

 

[dirtrider]

1 hour ago, Michaelr11 said:

When I was having a problem with fuse blowing on my airhead, this is what I did.

 

Hook up a turn signal bulb or headlight bulb with a wire pigtail. Remove the fuse that keeps blowing, and connect the two wires for the bulb into the fuse holder, one wire at each side. This will set up the bulb in place of the fuse. If the circuit is on and working, the current will just run through the bulb,. It will either be off or it will glow slightly. As soon as you connect or turn on the problem part, or move the wire that is grounded, the bulb connected to the fuse holder will turn on bright.  This will let you check all of your circuits without continuously replacing fuses.

 

Morning   Michaelr11

 

That works OK for a constant ON circuit or for a normally OFF circuit that has a low load when on, but when working with the fuel pump circuit it becomes difficult to use as the pump (entire pump circuit) only cycles ON for a second or two at key ON then back off again. The light will flash bright at key-on but who knows if that is a proper light due to normal fuel pump & circuit load or too much light due to a short or excessively high pump load? It happens so fast that he will probably need a 10 amp fuse to instantly blow to tell much. 

 

A turn signal bulb will definitely light to full brightness fusing the fuel pump  circuit so that won't be useful. A 55 watt headlight bulb will light at about full brightness at a 12v 5 amp current so would be difficult to tell  a short to ground or just normal circuit load in a 1-2 second light flash.

 

There are only a few things to disconnect it order to eliminate each circuit branch so shouldn't be a lot of blown fuses to deal with. 

 

I suppose he could even do it with 1 fuse if he first disconnects all that is on the fuel pump circuit then one by one plugs each back in with a test key-ON test after each addition. The one that blows the fuse is the culprit. 

 

If it still blows with all disconnected then the light bulb trick might be used in conjunction with a new 10 amp fuse then removing the fuel pump relay & jumping the relay socket 12v B+ terminal  to the 12v out terminal with the headlight bulb or turn signal bulb.   

 

 

 

 

  

[Balibeemer]

DR. Sorry for the late reply but I only got back 2 days ago.
OK, I think I found the problem! The two green wires coming out of the bottom of the fuel level sensor were missing some insulation that was very brittle. I don't have access to fuel resistant cables and was thinking of 'insulating' each cable with epoxy.. Would this work short term (I'm moving house soon) or should I try to rewire the entire fuel sensor and cover it with heat shrink tubing?. 

Edited January 18 by Balibeemer
Spelling

[dmsantam]

The problem is that most heat shrink tubing is not fuel resistant when submerged in fuel constantly. 

 

I used some Tygon tubing (DR suggested this to me a while back), which will likely harden up with constant fuel contact, but I think it'll be fine. 

[Redfoxx]

1 hour ago, dmsantam said:

The problem is that most heat shrink tubing is not fuel resistant when submerged in fuel constantly. 

 

I used some Tygon tubing (DR suggested this to me a while back), which will likely harden up with constant fuel contact, but I think it'll be fine. 

You think the cause then is it was shorting between the wires since so close to arch or toughing. The gas should act as more of a insulation if you have enough seperation.

[dirtrider]

On 1/18/2024 at 4:57 AM, Balibeemer said:

DR. Sorry for the late reply but I only got back 2 days ago.
OK, I think I found the problem! The two green wires coming out of the bottom of the fuel level sensor were missing some insulation that was very brittle. I don't have access to fuel resistant cables and was thinking of 'insulating' each cable with epoxy.. Would this work short term (I'm moving house soon) or should I try to rewire the entire fuel sensor and cover it with heat shrink tubing?. 

Morning Balibeemer

 

Those wires should be replaced or covered. But I don't think that is your fuse blowing issue.

 

Nether of the wires coming out of the fuel level sensor shorting to each other should be able to blow the fuse. (I think you have something else going on inside the fuel tank that is blowing the fuse)

 

Any (under fuel) wires should be special fuel-submersion-resistant wiring. 

 

Or, you can cover the wires with fuel submersible hose (very expensive).

 

The cheapest way is to use new fresh pliable Tygon tubing (hose) as most of that is fuel resistant but it WILL get stiff as heck after being submerged in fuel for a while so future work in that area will be more difficult due to the very stiff Tygon wire covering. But if you are only covering a short section of the green wires then that isn't a big deal to work with in the future. 

 

In any case, before calling it repaired make darn sure that you have found the short as I don't think it is in those green fuel sender tube wires shorting together. 

[Balibeemer]

I replaced the fuel pump and now everything works!