Fuel pump wiring problem

[ed3541]

Hi,
I have a '91 K75 with a fuel pump problem. I have 12volts at the female connector under the fuel tank when I hit the starter button ( from the green/white to brown wire). I have continuity in the green wire of the male connector to the yellow wire for the pump. I also have continuity from the brown wire of the male connector to the black negative wire for the fuel pump. But I get no power to the pump when I press the starter.
The relay is closing - I took the cover off and can see it close when I hit the starter. I have power on both sides of the #6 fuse. One time I noticed 12 volts at the pump wires without even hitting the starter button. But most of the time-  I get no power to the pump.
I would appreciate the help.

[Martin]

The four pin connector is a known source of conductivity problems. Deoxit will sometimes fix it, or replacement with a good quality water proof 4 in connector.  With the cap up or removed try wriggling the 4 pin connector while listening for the pump, you should also be able to observe the fuel returning to the tank. The other thing does your pump actually work. You can remove the pump from the tank and apply 12v direct to the pump, by connecting leads to the pump first then to the battery.
Regards Martin.

[ed3541]

Hi Martin,
Thanx for the reply. Yes the pump works - I applied direct 12 volts to it. I even bought an aftermarket pump when I bought the bike cause the previous owner said it had a bad pump. But the original pump works and so does the aftermarket one.  You could be right about the connector - I may wire it up direct to see if that works - then get another connector. Luckily  I have another k75 that runs great so I have a great bike to ride while I work on this one.
thanx,
Ed

[Martin]

I have had my 25 year old brick for twenty years before experiencing problems with the connector. After using DeoxIT it still played up a couple of times but would respond to being pulled apart and reassembled. I decided to fit a Duratech from Jaycar, I had to find the assembly instructions off the net as there were no instructions included. I used the DeoxIT gold on assembly, I am happy with my choice but there are others out there that may be equal or better.
Regards Martin.

Duratech 2.jpg (83.74 kB . 768x576 - viewed 856 times)
Duratech 3.jpg (60.36 kB . 768x576 - viewed 896 times)

[rbm]

When the OEM connector goes bad, many choose to use a 4-pin trailer hitch connector as a replacement.  These are sold with mating connectors on a short jumper.  Cut the jumper halfway and connect up the 8 wires.

Alternatively, buy a connector like Martin suggests or a Amp Superseal or a Duetsch DT series.  Both are available from Ebay for cheap.