Help in understanding my dual tank setup

[liftlid]

If the pump noise goes from loud knocking to a softer tap tap it is just priming. A few things for you to check below.
Is it your low fuel light that is blinking ?
Could it be the fuel from aux tank making float bounce ?
What port on main tank is pump outlet hose attached to?
Is the fuel sender on aux tank wired up?

[matfew]

Where are you located mate. I'd be keen to have a look and try work it out for you. I just wanna see how it's setup for my own when time comes to lol

[liftlid]

Another question?
Does the pump switch have 3 positions?
Pump on
Main tank gauge
Aux tank gaugeImageUploadedByMotorculture1387485501.613751.jpg

[Flo-w]

Another question?
Does the pump switch have 3 positions?

Only 2 positions: on / off and a light which can be either on, off or blinking. It's off when the switch is off, it's on or blinking when the switch is on.

It's not a low fuel light that's blinking as there should be at least 30l in that aux tank now.
I don't think there's a fuel sensor on aux tank as I don't have a fuel gauge for aux tank.
I'll have to crawl underneath...

[threedogs]

@ liftlid that's a duel fuel switch by the look of it, for switching from petrol to gas
It will have 3 positions as you need to run petrol dry before using gas otherwise it will dual fuel and run like a dog

[liftlid]

@ liftlid that's a duel fuel switch by the look of it, for switching from petrol to gas
It will have 3 positions as you need to run petrol dry before using gas otherwise it will dual fuel and run like a dog

My picture was of a my diesel change over switch, g = gauge(aux tank)
Centre is main tank gauge, pump is to turn pump on to pump from aux to main tanks

[liftlid]

Only 2 positions: on / off and a light which can be either on, off or blinking. It's off when the switch is off, it's on or blinking when the switch is on.

It's not a low fuel light that's blinking as there should be at least 30l in that aux tank now.
I don't think there's a fuel sensor on aux tank as I don't have a fuel gauge for aux tank.
I'll have to crawl underneath...

Assuming that the blinking light is on the switch and not the low fuel light on the dash I wonder if the light starts blinking when the pump has pressure? If so you might find a pressure switch somewhere.
Another far fetched idea is that the pump is faulty and the circuit is fed through a circuit breaker which is tripping and re setting causing the light to start blinking, long shot but if the pump is not pumping ????
A standard tank holds 95 lt and you will have about 20 lt left when on empty.