Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Fuel Pump Gone?

[weeksy2]

Originally Posted by spinoli1

'Fraid I dunno. Not very clever when it come to electricals.

All I found was -

Goosed relay - no fuel pump prime sound - stay where you are.
New relay - fuel pump music - depart for lots of laps.

Relay is not expensive - so well worth trying first.

Spin

is it something one of us can take off our bikes quickly for a test mate ?


If so, where are you based Ip.

[spinoli1]

Not sure if the relay is common to all 748/916/996/998.

Look underneath the battery - by memory there are 2 little black boxes (large sugar cube size) in rubber holders. One is the indicator relay, the other for the fuel pump. There may be more than 2.

Simply unplug to replace/swap.

Spin

[lp1967]

Weeksy - I'm north of the Border mate.

Have ordered a couple of spare relays so will hopefully get a chance to try this at the weekend and post a reply thereafter.

Cheers guys.

[moor-ph0]

Hi,
The fuel pump relay supplies the +12volts to the fuel pump if all conditions are satisfied i.e sidestand switch etc. If your measuring +12 volts at the fuel pump connections then in theory the relay is okay. However the pads of switched relays become pitted with time resulting in, effectively a dry joint which shows up as a high resistance. Basically if unloaded can easily measure 12volts (similar to unloaded batteries) but when loaded by the pump causes all the voltage to drop across the pitted relay pads. If your measuring the voltage with the pump installed then the chances are it's the pump. One final test before I would replace the pump would be to short out the switched connections on the relay socket. If it still doesn't work then I would try to run flying wires from the battery directly to the pump interconnect. This would eliminate the wires in the loom.
Hope this helps.

Geoff

[lp1967]

Gents

Thanks all for your help. Replaced the relays with a couple of new ones (for the price I didn't see the point in working out which was which) and the fuel pump whirred into life.

One worrying thing however - my *pristine* bike does not have *any* corrosion *anywhere* on it, but after leaving it connected to an Optimate for almost a year, I noticed heavy "powdery" corrosion on:

The battery mounting bracket
Parts of the regulator
One of the bellypan Dzus fasteners
Many spade connectors (including the fuel pump relay, the fuel pump power supply and the sidestand)

I can't help but think this must be some electrically-induced problem.

Any comments?

[geoffp]

One thing to be wary of is that the process of charging a battery does give rise to acid vapours in small quantities and these can cause corrosion of the area immediately surrounding the battery unless the area is well ventilated (like when you're riding.....) This would probably account for the mounting bracket, regulator (isn't it just below the battery?), and possibly some of the other connectors). It's also possible those vapours emanated from the battery overflow (that's one of its purposes) ending up in the belly pan, possibly affecting the sidestand (not much down there that's made of metal eh!)

It's always best to take the battery out and leave in a well ventilated area when on charge for long periods. Or get a sealed battery..

[alb916]

New relays did the trick first time with my 916 but in the end I installed a new wire to the fuel pump due to the resistance in the existing wire (even though it was measuring 12+V) still causing it to play up. cheers

[Nozza]

Guys, thanks for your threads on this one. Just replaced the fuel pump relay (left hand black 'sugar cube' below the battery - the right one is the indicator relay) after no whirr from the fuel pump on start. Bingo! Lot of time saved and now off to IOM TT 2010!