Thread: Single VDO gauge for main and sill tanks??

Single gauge and toggle will work fine. I have that setup in my IIA.

do it with a DPST switch.

one pole goes from the gauge to either sender the other provides power to the pump.

combine it so that when the pump is on you're reading the sill tank.

very roughly it would look like this

Wire to gauge-----------------|
wire to sill tank sender -----O O O----wire to main tank sender
Wire to transfer pump------O O O
Ignition switched power wire--|

IF you're already using an electric pump to lift the fuel you could just do it the dead easy way Tpiece the the transfer pump in after the outlet of the normal lift pump wire up the normal pump to come on when the main tank is turned on and then let the return line take care of filling the main tank for you when you switch over to the sill tank.

Steve,
I had one gauge that would read all three tanks in my County. It was a pretty simple setup as far as wiring goes, so it's not a problem. The only difference is mine feeds straight to the engine from whichever tank is switched to, instead of topping up the main tank from the aux. This was achieved by using two three-way solenoid valves. I had a three position switch on the dash which would simply switch from tank to tank as well as switching the gauge.
The solenoid setup negates the need for extra fuel pumps. In the case of solenoid failure the system will feed from the main tank only, but it's a simple matter of swapping a couple of hoses on the solenoids to access the other tanks if needed. The same two solenoids have been on my County since 1988 without any problems, so they're pretty reliable.

I have since changed to having a separate gauge for each tank so I can see my total fuel at a glance, but still have the switch for the valves.

Cheers, Murray

being all vdo will work I set up a s3 swb with twin tanks years ago and used a toggle for the gauge, switch also powered a solinoid to switch suction from tank to tank. it was very neat as the standard dashswitch was used after rewiring the dash switches to my own arrangement(dash lights moved to be powered from headlight switch from memory) but remembering 18 years and many scotches back

Originally Posted by Blknight.aus

do it with a DPST switch.

Don't you mean a DPDT switch?

yep, was late last night, DPDT it is...

Originally Posted by rijidij

Steve,
I had one gauge that would read all three tanks in my County. It was a pretty simple setup as far as wiring goes, so it's not a problem. The only difference is mine feeds straight to the engine from whichever tank is switched to, instead of topping up the main tank from the aux. This was achieved by using two three-way solenoid valves. I had a three position switch on the dash which would simply switch from tank to tank as well as switching the gauge.
The solenoid setup negates the need for extra fuel pumps. In the case of solenoid failure the system will feed from the main tank only, but it's a simple matter of swapping a couple of hoses on the solenoids to access the other tanks if needed. The same two solenoids have been on my County since 1988 without any problems, so they're pretty reliable.

I have since changed to having a separate gauge for each tank so I can see my total fuel at a glance, but still have the switch for the valves.

Cheers, Murray

Any chance you've got a brand or P/N for the solenoid valves Murray?

I like the idea of switching the feed between tanks as it gives complete isolation between tanks, but wasn't sure about the return side of things since the normal return only goes into the main tank. Usually it wouldn't be an issue if there was space in the main, but if you ran from the sill tank with the main full would the return into the main cause it to overflow?

Steve

Can't help with P/N's, but the valves I have are Pollak brand.
I have two of these three way valves linked up so that when neither is energized the fuel is drawn from the main tank, when one is energized it comes from one of the sill tanks and when both are energized it comes from the other side sill tank.
Obviously for a two tank setup you only need one.

This is the type I have.


This is a newer type with 6 ports in the one unit and a nice neat wiring loom.


I did a quick search and it looks like there are other, more robust units out there too.


During my image search, it seems these type of valves are popular on biodiesel forums.

Cheers, Murray