25 replies to this topic

[Fred320]

Options on what checks need done?

[GraemeC]

Inertia cut off switch?

[Fred320]

No cut off switch. It's a wiring issue as there is no power getting to the pump. Somewhere from under the bonnet to the ignition. I think.

[GraemeC]

Telling us what the car is would help

[sonscar]

Start at the pump and check for battery and earth preferably with a test light.See if either of them is missing.Do not rule out the pump having failed.Steve..

[Fred320]

I have checked a number of things - pump works as connect it to battery, earth is good.
Checked wire diagram and shows interior light is in series with pump. The interior light works so I believe it's the positive wire from the light to the pump that is the issue? Is it possible that relay is faulty? I ask as if the interior light is working and they are in series you would think the light wouldn't work too.

[Fred320]

The car is a 1978 1000cc Leyland mini with a unknown 1275cc engine and some more modern wiring fitted. I brought it in this condition and was told these details.

[nicklouse]

What pump?

[DeadSquare]

I have checked a number of things - pump works as connect it to battery, earth is good.
Checked wire diagram and shows interior light is in series with pump. The interior light works so I believe it's the positive wire from the light to the pump that is the issue? Is it possible that relay is faulty? I ask as if the interior light is working and they are in series you would think the light wouldn't work too.

 

 

I have checked a number of things - pump works as connect it to battery, earth is good.
Checked wire diagram and shows interior light is in series with pump. The interior light works so I believe it's the positive wire from the light to the pump that is the issue? Is it possible that relay is faulty? I ask as if the interior light is working and they are in series you would think the light wouldn't work too.

 

As electricity is getting to the interior light, just replace the wire from the light to the pump.

[DeadSquare]

Move the pump from the rear subframe and mount it by the wiper motor where it is dry.

 

Feed the electricity to it from the dashboard light switch, so that by turning off the dashboard lights, the electricity is cut off from the pump.

 

Someone driving away without turning on the dashboard lights will only get about 100 yards before the engine cuts out due to lack of fuel in the carburettor.

 

Don't let your wife use your car.  It would only have to stop after 100 yards once for you to get no supper and definitely no "Wink, wink --- Nudge nudge"

[ac427]

I have checked a number of things - pump works as connect it to battery, earth is good.
Checked wire diagram and shows interior light is in series with pump. The interior light works so I believe it's the positive wire from the light to the pump that is the issue? Is it possible that relay is faulty? I ask as if the interior light is working and they are in series you would think the light wouldn't work too.

Wired in series?
Wouldn't that mean if the bulb blew, the pump would cutout?

[humph]

When you say the wiring diagram shows it’s fed from the interior light am I right assuming this is a custom wiring diagram? The subframe mounted fuel pump is normally fed by a white wire directly from the fuse box, there’s a joint between front and rear looms by the wiper motor on mine. If someone has added a wire from the light to the pump is there continuity if you connect a voltmeter to each end? If not then running a new one shouldn’t be too difficult.  You also mention a relay, is there one?  If you listen closely you should here a click from the relay when someone turns the ignition on powering the relay, or remove it and test with a multimeter

 

 

https://www.electron...h-a-multimeter/

[DeadSquare]

 

I have checked a number of things - pump works as connect it to battery, earth is good.
Checked wire diagram and shows interior light is in series with pump. The interior light works so I believe it's the positive wire from the light to the pump that is the issue? Is it possible that relay is faulty? I ask as if the interior light is working and they are in series you would think the light wouldn't work too.

Wired in series?
Wouldn't that mean if the bulb blew, the pump would cutout?

 

Yes, it would.

[DeadSquare]

In my BMC Workshop manual, the wiring diagram shows the fuel pump is fed from A3 on the fuse, by a white wire all the way, with one bullet connector in the line.

 

The interior light is fed from A2 by a purple wire all the way, also with one bullet connector in the line.

 

Neither the fuel pump nor the interior light, feed any additional electrical items.

[Fred320]

I have replaced the relays there all good, fuses are all good. The interior light (in br/gr to light, w/p & n/s out)does run in series with the (w/p)pump and (n/s)fuel gauge sensor. No power seems to be getting to the pump and sensor. I have taken a wire from the light w/p connect to pump and earth it. There is power but not constant and not 12volts ( when I switch the on flickers is not bright). Does this mean either there is a earth problem or short? The wire diagrams I have only show one wire going in to the light and one going out.