Fuel Pump problems

Post by **kitco** » Sun Dec 04, 2005 11:14 am

The fuel pump on my '64 Minor 1000 used to work fine, but a wire has broken. It was connected to a switch inside the driver glove compartment, but the switch has only one terminal, so can't possibly do anything. Can anyone tell me how the fuel pump should be wired,just connecting the earth and positive doesn't seem to work.

Post by **Packedup** » Sun Dec 04, 2005 11:47 am

White (non-fused ign dependent) to pump. I think the white feed comes off the back of the ignition switch, but I can't remember for sure. Got a feeling the pump earths through the mounting bolts, I certainly can't remember hooking an earth wire up to it at all.

If you don't have a multimeter/ voltmeter to check the wiring, then get a spare 12v bulb and test the white wire with that... Electrical niggles are so much fun without any test gear!

Post by **ColinP** » Sun Dec 04, 2005 3:29 pm

Hi,

My pump has two wires:

power is from the ignition cirsuit (i.e. power only when ignition switch is on - obviously?)

earth is via a small black wire from the pump body to earth at the mounting bolts (It may well earth through the body as well).

Some of the pumps are supposed to be +ve earth, some are happy either way. (I'm guessing the capacitor in the top may be to blame).

luck,

Colin

Post by **Willie** » Sun Dec 04, 2005 4:05 pm

I would imagine that your switch in the glove box was an anti theft device.
The pump is fed from the fuse terminal A3 (the one with all the white wires
on one end of the fuse and green wires on the other end) It is NOT fed through the fuse just teed off of it. The earth(chassis) connection is made
through the two fixing bolts but there is an additional thin wire from there to
the part of the pump above the diaphragm because said diaphragm could act
as an insulator .

Post by **kitco** » Sun Dec 04, 2005 4:21 pm

Now I know it's wired OK, I've found that it doesn't work, however, if I disconnect the positive, and repeatedly tap the wire against a live point, the pump will pump one squirt of fuel each time I do this. I don't have a manual, so can anyone suggest anything... My email address is alex@k-it.co.uk if anyone has a diagram, etc.

Post by **Willie** » Sun Dec 04, 2005 4:26 pm

Kitco.... your symptoms suggest that the points are not making good contact
except when you flick the feed wire 'on' so that the initial surge is just enough
to give one 'tick'................Clean the points, you could be lucky.

Post by **kitco** » Sun Dec 04, 2005 4:28 pm

How do I clean the points - I have no manual...any help appreciated.

Post by **Willie** » Sun Dec 04, 2005 5:07 pm

The simplest way is to wipe a piece of card across the points. If they are
really dirty and cratered then you can remove the outer contact blade by
loosening (not necessary to completely remove it) the retaining screw and
sliding it out. Then you can clean it properly with a file or oil stone if it is
necessary. I have told you in another thread on 'electrical' that the points
are underneath the plastic cap on the terminal end.

Post by **bmcecosse** » Tue Dec 06, 2005 1:34 pm

You NEED to get a manual ! The switch in the gbox must have had two terminqls - one has broken off. But once you take the plastic cover off the pump you will see the points mechanism - some have one, some have two. Clean them as described above. Any capacitors around the pump are just there to supress sparks for wireless reception purposes.

Post by **kitco** » Tue Dec 06, 2005 1:41 pm

I cleaned the points, and now have a perfectly running car. The switch was redundant, don't know what it originally did.
Thanks for everyone's help.

Post by **ColinP** » Tue Dec 06, 2005 4:00 pm

Any capacitors around the pump are just there to supress sparks for wireless reception purposes.

Should also reduce the arcing across the points - but if one of them is an electrolytic, connecting it the wrong polarity = fried capacitor.

That dumps corrosive stuff onto the circiut board, and shorts out....

Mine (new one) is fine for +ve or -ve earth, but there are all sorts of possibilities (e.g. home repair?)

The swithc may well have been a "security" device - that is now redundant.

Glad it all works,

Colin

Post by **pskipper** » Tue Dec 06, 2005 4:05 pm

Where abouts are you kitco? If you are in the wiltshire area I have a Haynes manual you can have if you want to collect it!

Post by **kitco** » Tue Dec 06, 2005 4:12 pm

I'm in london, but I'm happy to pay for the postage...

Post by **pskipper** » Thu Dec 08, 2005 9:44 am

Okay, I'll find out the postage at the weekend and then pm you to let you know/get your address!