6x6 fuel tank changeover

[Rob6x6]

G'day all,
The changeover switch for the fuel tanks has stopped working.  I wanted to check the fuse however I can't locate it at the moment.  I opened the fuse cover and it said something like fuse for changeover switch and ambulance siren (if applicable) is located behind the ashtray.  I removed the ashtray and shone a light in and couldn't seem to locate it. 
When I turn the ignition on the fuel gauge will shoot straight up to full however this is not correct.  Any clues as to where to look.
Cheers, Rob

[Notlongnow]

Rob, you may need to dig pretty deep behind the ashtray to find those fuses. They can get hidden behind a rats nest of wires.

However, if it is just the fuel gauge you are concerned about, it is unlikely to be a fuse at fault. It could be a bad connection on the fuel change-over relay. There is a press-tag on top of the electrical connector - press that and you should be able to remove the connector. Make sure it is clean and dry, and refit. Also worth checking the connector on top of the fuel tank. The 'spade' terminal is the gauge, the bullet type is for the low fuel warning light.

Good luck,

Paul

[Rob6x6]

Thanks Paul,
I have had a good look into that rats nest and cant pick up a fuse.  I am thinking of getting one of those cheap little inspection cameras to dig deeper.
Can you tell me where the fuel change over relay is located.
Appreciate any further assistance.
Cheers, Rob

[dugite]

Can't help with relay location but ... is there a relay for the changeover switch ?

In my 4X4 RFSV, 5 of the relays are mounted in the main fuse box.

The Pollak valve (changeover valve) has a special strip connector which is somewhat exposed down between the tanks.

I think I would start by cleaning the connector contacts.

This electrical connector also changes the fuel gauge selection when the selector is switched.

[Rob6x6]

Thanks Dugite,
I think that's what I will try. Go straight to the Pollak valve and give the connections a clean and good spray of Parrots P..s. I could well have picked up some moisture and crude in the connection.  Agree its location is pretty exposed to some harsh elements.
Cheers, Rob

[dugite]

Wipe any excess cleaner to avoid tracking and shorts, it is a neo coated strip on the side of the Pollak.

I hope it helps.

[Rob6x6]

Thanks Dugite,
Will let you know how I go.
Cheers Rob

[Notlongnow]

Rob, if it is just the fuel gauge reading full you are concerned about, do check the fuel sender connections on the top of your tank, especially if it only has the fault on one tank.
If it happens on both tanks, it is more likely to be the aforementioned connector on the fuel change-over relay (Pollack valve).

[Rob6x6]

Thanks Blokes,
Will give it a crack over the weekend.
Cheers, Rob

[dugite]

pin marked "B" on the connector is for the fuel gauge

[dugite]

here you go

schematic view of Pollak valve wiring

[dugite]

Just for reference if you want to purchase a genuine Pollak , they're available from the importer Scintex in Brissie, who actually sell them them slightly cheaper on clickandcollect ebay

Plenty of quite cheap clones on US ebay where all the "good ol' boys" use them with all the extra tanks in their "trucks" - dunno if these clones are any good.

[Notlongnow]

Remember when testing the fuel gauge connections that a BROKEN connection gives a full+ tank reading, while a short to ground will show empty. You seem to have a broken connection - between the Pollack and the gauge if it is on both tanks, or between the pollack and the tank sender if only reading full on one tank.

[Rob6x6]

Thanks Fellas,
I pulled the wire connector out of the Pollak valve and sprayed it with some silicone lubricant gave it a wipe put it back in and no joy.  So the fuel gauge is showing full on both tanks could it be the Pollak valve is had it?  I will mention that I have been playing with the dash recently to get the dash lights working better but everything was working fine.  Do you think a wire could have worked off the back of the fuel gauge and if so would this give a full tank reading?
Cheers Rob

[Rob6x6]

Just looked behind the fuel gauge and all the wires seem ok.