Bloody sub tank in GU 2007 dx patrol

[grubkenbel]

hi
couple of probs

1.Had a full sub tank and a 1/4 main tank yesterday and switched the sub tank switch to on which seemed to work but sub tank needle decided to go haywire and drop down to half a tank (when we know for a fact it is full)
then switched back to mains tank which the needle went from 14 up to half a tank in the main
what is the go with that are the sensors in the tanks fuc*** or wiring to the tanks stuffed?
also no dash light came on to indicate the sub was in use.

2. full sub tank half main tank we decide to switch the sub tank on again and it lights up on the toggle switch then goes out on the toggle switch and did not light back up just took it for a drive to check the flood water levels and switched it to sub tnak to see if light will work it did for 5 mins then went out. all the time there is no light on the dash

help this car is pissing me off we are finding one thing after another...................:(

[BearGUST]

I'm a bit confused, are you aware that the sub tank just has a transfer pump to pump fuel into the main tank? The sub tank level will drop and the main tank level will rise...

[wildgu6]

Hey buddy, there's a couple of threads re sub tanks doing same thing, will find and post up when get time. It's a common prob' for some. Or you can type sub tank into the search bar and it should come up. Good luck buddy

[wildgu6]

Found this one buddy, have a read n see if helps
http://www.nissanpatrol.com.au/forums/showthread.php?t=8332

[Maxhead]

I'm a bit confused, are you aware that the sub tank just has a transfer pump to pump fuel into the main tank? The sub tank level will drop and the main tank level will rise...

I agree, you switched the sub ON which means you are transferring diesel from sub to main. That's why the needle went to half tank as it transferred to the main tank. It takes about 20-30 minutes to transfer the whole sub to main.
Also the transfer will shut off automatically when the sub is nearly empty and the light will go OFF on the switch. That is normal

[wildgu6]

After reading your post again, I have to agree with Kris & Co. That is normal.

[grubkenbel]

the light goes off even when the sub tank is full and it is switched over

[grubkenbel]

ok we had the sub full and switched it over for 10 mins then the needle on the sub tank dropped to half rapidly yet they are saying it takes half an hour to fully transfer so why is it down to half so quick?

[the evil twin]

If it dropped to 1/2 in 10 minutes thats normal... it will take about 20 to 25 minutes to transfer the full 30 litres.

The pump transfer rate is approx 1.5 LPM. It will vary from vehicle to vehicle

The light on the instrument binnacle is a failure light. If it comes on then something is stuffed.

The light on the switch is 'on' when the transfer pump is selected and running. The Pump will automatically turn off when either the Sub is empty or the Sub Tank Computer thinks there is somewhere more than 1/2 to 3/4's in the main.

If there is fuel in the sub it will do a small self test EVERY time you start the engine. This means if you do a lot of stop engine / start engine useage pattern then you can expect to see as much as 5 to 10 litres a week go from the sub to the main even tho you didn't 'select' it.