blown fuel pump fuse

[genewilliamsgene]

Hello all,


So I had been having a problem with a fuel pump blowing intermittently for awhile and I could not figure it out, I replaced the old wires that went into the under-tank termination (they were stiff and the insulation snapped instead of flexing, this did not fix it. I tested the pump and it was not seized, but it was not running on startup and it was blowing the fuse when I pushed the starter. I really couldn't figure it out and I didn't want to take the loom apart, anyway I charged the battery because my troubleshooting was probably running it low and it started up once the battery was at full charge! no blown fuse!
Does this make sense to someone who knows more than me about electricity?


Side Note: my tank is missing the insulation, how important is this and what should I use as a replacement


Thanks,
Gene

[Laitch]

my tank is missing the insulation, how important is this and what should I use as a replacement

Use Reflectix. Building supply stores usually have it. It will keep the tank cooler therefore your legs cooler.

Wires traveling from the fuel sender in the tank to the fuel pump might be shorting to blow the fuse. Did the wires attached to the pump have continuity?

[Martin]

You will also reduce the chance of fuel vaporization. You can also use aluminium tape in places where you can't fit the Reflectix. A good way to check the wiring is to connect a multimeter or a buzzer in place of the fuse and start moving the wires around work your way along the harness  until the multimeter jumps or the buzzer sounds. Or you can do the same with the fuses if you have enough of them.
Regards Martin.

[genewilliamsgene]

Alrighty, so I thought my problem was gone, it is not. I tried to start up the bike and I blew another fuse on the fuel pump, however this one was strange everything worked correctly as the bike started up however when I revved heavily it blew the fuse. I searched and searched for a short w/o the pump attached and I am almost positive it is the pump, does this make sense to you guys?


Thanks,
Gene

[Laitch]

I tested the pump and it was not seized, but it was not running on startup and it was blowing the fuse when I pushed the starter.

How did you test it. Did you remove the pump and run current through it on the bench?

[genewilliamsgene]

That is correct.

[Scott_]

So while you have the pump out of the bike, obviously it won't start, but have you tried the starter button to see if the fuse blows again....

[genewilliamsgene]

So while you have the pump out of the bike, obviously it won't start, but have you tried the starter button to see if the fuse blows again....

yep, cannot get the thing to blow without the pump.


However every once and awhile it will run for a few min and then blow, this morning that happened and it blew only after I revved it for awhile.


The fuel pump is new btw, from what I can tell it looks like a kit was purchased, everything in the tank looks pretty new.

[Laitch]

yep, cannot get the thing to blow without the pump.

If your horn works, try using its relay in the place of the pump relay. Keep your fuse supply topped up too. :giggles

[genewilliamsgene]

If your horn works, try using its relay in the place of the pump relay. Keep your fuse supply topped up too. :giggles

so true, off to get more fuses, I switched the relays and the horn works with the fuel pump relay and the fuse blew with the horn relay  :help:

[genewilliamsgene]

a little additional info i forgot to add, the fuel pump relay was pretty warm when I pulled it out.

[Laitch]

I replaced the old wires that went into the under-tank termination (they were stiff and the insulation snapped instead of flexing, this did not fix it.

Did you replace the 4-pin connector, too? Lack of clean, tight contact between the pins and the sockets of this connector could blow this fuse.

[genewilliamsgene]

Did you replace the 4-pin connector, too? Lack of clean, tight contact between the pins and the sockets of this connector could blow this fuse.

I did not replace the plug but i cleaned it, re-pinned it (not sure if this is the right term but removed the wires from the female parts of the plug and put in new wires) and tightened up the female metal bits.
I could be wrong but I doubt this is where the problem is.


Is the idea about starting with the horn button legit? I can't tell if it is a joke or not.


Wouldn't this only work if the problem is the switch or a short on the way to the switch? i guess it could be one of theses things.

[Laitch]

I could be wrong . . .

I suppose that's possible. You might check it over thoroughly.

[kioolt]

Are you sure you are using the right size fuse?  You might want to try inserting an ammeter in line with the fuse or fuel pump to see what your actually current is.

[genewilliamsgene]

OK, I messed up earlier.  When I thought  switched the horn relay with the fuel pump I actually switched the fuel injection and the load shed relay.


So now  have switched the horn and the fuel pump relay, the fuel pump didn't run in this configuration but no fuse blew either.


I then put the relays in their correct configuration and it started up and ran fine. I revved the motor and nothing blew.


Could a bad connection at the relay cause the fuse to blow? It has ran for a few hours in the past without blowing the fuse so i'm not sure I trust it yet...

I am running a 7.5 which i believe is correct...
Are you sure you are using the right size fuse?  You might want to try inserting an ammeter in line with the fuse or fuel pump to see what your actually current is.

I am going to take a look at the back of the female connection for the fuel relay and see if there is anything fishy going on there. The only thing I can figure is that perhaps there is a short back there unless a bad/ dirty connection at the relay can cause a short.

[genewilliamsgene]

Sorry, I messed up that quote. The first line is me, I am running 7.5.


I checked the back of the relay socket and everything looks fine and dandy so IF my problem is fixed it was a bad connection at the relay that caused the fuse to blow.


Does this make sense or is that possible?

[Laitch]

Does this make sense . . . ?

Perhaps it was a faulty/dirty connection into which the relay plugged that was causing this, and that the connection was cleaned by repeated insertion and removal of relays? Perhaps. If it works, clean those connections well and be happy.

[genewilliamsgene]

Well, I went out today and it blew the fuse again... I'm going to have to dig into the wiring diagram. ugh.
this old thing is starting to push my buttons...

[Inge K.]

Disconnect and isolate the smallest fuel pump terminal, to eliminate if it is the fuel pump (or something else)
that draws to much power.
If the fuse still blows, next step would be to disconnect the connector under the left front of the tank.

[duckytran]

I had a similar problem with my 7.5a fuse continually blowing. What we do have in common is a new pump. I ended up using a higher amp fuse 8.5 and it's working fine ever since. You can give that a try.

[genewilliamsgene]

I had a similar problem with my 7.5a fuse continually blowing. What we do have in common is a new pump. I ended up using a higher amp fuse 8.5 and it's working fine ever since. You can give that a try.

I didn't have and 8.5 so I swapped a 10a fuse just to do some quick troubleshooting, with the 10 a fuse nothing blows but the pump does not turn, i'm not sure what this means.  :dunno2:

[genewilliamsgene]

Disconnect and isolate the smallest fuel pump terminal, to eliminate if it is the fuel pump (or something else)
that draws to much power.
If the fuse still blows, next step would be to disconnect the connector under the left front of the tank.

I did this earlier and the fuse didn't blow once the pump was disconnected, however the problem has been intermittent so i'm not sure that this test can be trusted. I'll do it again and try to verify.

[Bosstomyano]

[size=78%]Any updates Gene? I'm having the same issue. New enduralast pump 2 years ago from EME worked in summer/fall started blowing fuses in the spring. Contacted EME got replacement and fixed the issue. Fast forward to now and same issue popped right back up. 7.5a fuses popping at ignition or soon after. Haven't tried the 10a fuse but I've torn everything else apart cleaned checked and swapped relays and still it's always the pump. I'm going to try the 10a fuse later today. [/size]

[genewilliamsgene]

[size=78%]Any updates Gene? I'm having the same issue. New enduralast pump 2 years ago from EME worked in summer/fall started blowing fuses in the spring. Contacted EME got replacement and fixed the issue. Fast forward to now and same issue popped right back up. 7.5a fuses popping at ignition or soon after. Haven't tried the 10a fuse but I've torn everything else apart cleaned checked and swapped relays and still it's always the pump. I'm going to try the 10a fuse later today. [/size]

No updates from me... I've been buzy with work so I haven't really been able to dive in and try to work on it. I think I'm going to do some work this weekend, I'll let you know if I figure anything out.


-Gene