6x6 fuel tank changeover

[dugite]

Hi Rob, can you hear the Pollak actuating when you function the switch when the ignition is "on" (engine not running of course) ?

I would expect that the Pollak valve itself is probably OK and I think your next project is to check continuity between the gauge, the switch, the Pollack and the fuel sender on the line connected at "B".

I would suggest referencing the schematic sketch I posted above.

As nothingnow has posted above, the gauge reads "full" when current doesn't get through to the earth at the sender, so the next most likely points are ...
1. power supply on lines at the switch which are connected to line "B" on the Pollak
2. the earths at the senders  - they may look "ok" but you need to verify them with jumpers or multimeter ,
3. check the selector switch itself and its connections, tested likewise

Even apparently good looking crimps can have continuity faults, and wires at crimp points can fray - have you got some Jaycar test leads and/or a multimeter ?

Frustrating I know, but it is all logical

[Notlongnow]

Rob, you should never, ever, EVER use silicon spray on electrical connectors. It is a great insulator. I think you should pull off the pollack connector again, get a small paint brush and a LOT of RP7/WD40 etc and scrub like mad on both parts.

[Rob6x6]

Paul,  yes I did realize my error and I pulled out the Pollak connection again and sprayed both ends with wd40 and cleaned it and sprayed it again and left it not connected for a couple of hours.   

Dugite, no I can not hear the the Pollak engaging when I switch it from one side to the other.  Which I would always hear when it was working.

Will keep digging.
Cheers Rob

[Notlongnow]

Keep at it Rob, you will get there.

You may have two faults - the Pollack not clicking means just that it is not changing tanks, it should be set on the last selected tank and the appropriate fuel gauge. (The Pollack also selects the correct tank for the gauge.)

So the two faults are
1, Not changing tanks
2, Fuel gauge not working on whichever tank is selected.

On mine, the change-over switch on the dashboard was full of dirt - as a temporary fix I just squirted some WD40 into the front while operating the switch back and forth. It is working for now, but will need to be replaced.

Cheers, Paul

[Rob6x6]

 Paul, I will try the wd40 trick into the front of the selector switch tomorrow and keep my fingers crossed.
.Another question.  How do I get the panel off which houses the control switch. I have undone the 2 machine screws but it doesn't want to move.  I can only presume that the vacuum switch, heater switch and cig lighter are some how stopping its removal. Because I would like to check the switch and it's connections.
Once again thanks for your assistance fellas.
Cheers Rob

[Rob6x6]

Another question fellas,
Do all the connection points on the back of the ignition switch need to be all hooked up. When I had the dash lifted yesterday I noticed there was one point that wasn't connected and there was a loose wire with a connector very close to it. 

Dugite, I see the schematic shows the change over switch is feed through a accessory power circuit.  I am wondering if this loose connection could be my problem.

I didn't want to just hook it up and try it in case I caused further problems.  What do you think.

Also when the ignition was on (engine not running) the reverse lights were not working could this be somehow all linked.

Cheers Rob

[dugite]

If it has original military wiring, the reverse lights only work with the engine running and reverse gear engaged.

Do you have a test light or multimeter? - either can be rigged between the unconnected terminal on the wire and any earth to see if there is power to the unconnected terminal on the wire when the ign is "on".

This possibly could be your problem (that it is unconnected)

[Rob6x6]

G'day,  Dugite and Paul
I tested the un hooked wire connector with ignition on and it had power.  Likewise the un hooked connector on the ignition switch also had power. 
I then found a in line fuse nearby I tested its continuity and it failed I then put another fuse in (admittedly it was a high rated one) and that connection got extremely hot straight away I turned the power off immediately because I reckon it was about to start smoking up.
I can only presume that this is the fuse for the Pollak.
My question is do you think that the loose wire connector and the connection on the ignition should be hooked up considering that they both have power individually when the ignition is on and this will somehow complete some strange circuit.
The plot thickens....
Appreciate any further assistance

Cheers Rob.

[Notlongnow]

It's a hard one Rob, trial and error with electrics can be fraught. I have a few electrical circuits here and so may be able to sus out what is happening if I can identify which circuit fits your model. What year is your 6x6, and what colour is the loose wire near the ignition switch? How many fuses are in the main fuse box? Tube or blade fuses? Where was the faulty fuse located - near the ign switch or under the ashtray?

[Mick_Marsh]

I tested the un hooked wire connector with ignition on and it had power.  Likewise the un hooked connector on the ignition switch also had power. 
I then found a in line fuse nearby I tested its continuity and it failed I then put another fuse in (admittedly it was a high rated one) and that connection got extremely hot straight away I turned the power off immediately because I reckon it was about to start smoking up.
I can only presume that this is the fuse for the Pollak.

What was the colour of the wire and trace to either side of this fuse?

[Notlongnow]

Something else to check - when you operate the fuel switch back and forth, a relay that controls the low fuel warning light should be heard to 'click'. On my 97 model this relay is behind the fuse panel, so it is easy to distinguish between the click of the switch and the click of the relay.
If you can hear the relay click, then you know that power is getting to the change-over switch so the fault will be in the wiring to the Pollack or the Pollack itself.

[Rob6x6]

I will see if a photo works. Not sure if I can get it to happen.

[Rob6x6]

That's the wire connector that is very close to the ignition switch.

[Rob6x6]

This fuse holder didn't house a fuse as first thought.  It is in fact a resistor.  Very strange never seen one before don't know what it is supplying.  That's why I didn't get continuity when I tested it.  However it has something like 96 ohms or thereabouts. I'm no auto sparkie by any stretch of the imagination I'm just trying to learn and winging it as I go.

[Rob6x6]

I have a 12/1990 model.  It has the later model  blade fuse box not the older glass style.