Random Wire

[HotRodPC]

What do you mean Aux tank? What do you call the Aux tank. The Left or the Right?

 

[MrMarty51]

What do you mean Aux tank? What do you call the Aux tank. The Left or the Right?

I always consider the left,as the main,as it is the easiest one to refill at the pumps.
The right tank,which means having to go around the pickumup to get toooit,I always considered as the auxillary.
Dont know if that is wright wrong or indrefferent,but,as stated,the switching valve is "SUPPOSE" to revert to that side if it fails,or the switch fails.
Notice: I use that word "SUPPOSE" lightly.

 

[HotRodPC]

I think you're right, but maybe not. Or maybe on ALL dual tank models, one tank is dominate, but I know the single tank trucks changed at some point. The Early squares a single tank was on the right. Later models the single tank was on the Left. I had just never heard then reffered to as AUX, so I thought maybe 1 was added. With all the common problems of the dual tanks, I'd be just as happy like I had in my 62, 1 tank was gauged, the 2 add on saddle tanks were not. Then it had the manual hand valve down by the driver seat. Pretty much fool proof. Nothing to go wrong really.

If I ever filled that truck up all 3 tanks, I know it held over 59 gallons. That was real nice to have back in So Cal when the gas rationing was going on, and that's exactly why the 3rd saddle tank was added. My granddad had owned the truck and bought it with main tank and 1 saddle. Seen the extra port for the 3rd tank on the valve, so he had 1 added. Then he had a gravity drain **** on the inside that noone could see. So he could drain one of the 23-25 gallon tanks for another vehicle.

 

[MrMarty51]

I think the "Auxillary tank" wording come from the early days of trucking,when,there was no go to the store for stuff,everything came from whatever them farmers/ranchers/truckers could scrounge up,valves from the hardware stores,tanks,to be added onto their trucks,come from salvage,either fo their own or something that had been abandoned by someone else,junk yards,where ever they could come up with anything that could/would fit.
Over here in Eastern Montana,it is rather desolate,county roads that a person can cruise on,for hours,and not seed another vehicle,just cattle,sheeeeps,and a deer or annelope or two.
Anything that can hold any extra fuel is almost essential,especially in them old farm trucks that gets maby two or three to the gallon,usually caused by not getting the proper tune ups and maintenance.LOL

 

[MrMarty51]

I think you're right, but maybe not. Or maybe on ALL dual tank models, one tank is dominate, but I know the single tank trucks changed at some point. The Early squares a single tank was on the right. Later models the single tank was on the Left. I had just never heard then reffered to as AUX, so I thought maybe 1 was added. With all the common problems of the dual tanks, I'd be just as happy like I had in my 62, 1 tank was gauged, the 2 add on saddle tanks were not. Then it had the manual hand valve down by the driver seat. Pretty much fool proof. Nothing to go wrong really.

If I ever filled that truck up all 3 tanks, I know it held over 59 gallons. That was real nice to have back in So Cal when the gas rationing was going on, and that's exactly why the 3rd saddle tank was added. My granddad had owned the truck and bought it with main tank and 1 saddle. Seen the extra port for the 3rd tank on the valve, so he had 1 added. Then he had a gravity drain **** on the inside that noone could see. So he could drain one of the 23-25 gallon tanks for another vehicle.

K00L story and experience You have there.I like stories.

 

[Boone83K10]

according to the schematic I have.. AUX for Auxillary is the passenger tank. My main tank is the driver side which is the one I was told works when I bought it. If the selector valve defaults to the passenger side when it fails, then that tells me it still works since I am on driver side. Nothing happens to the gauge when I switch it to passenger side (the needle doesnt move at all for an empty tank) so I assume the dash switch isn't make contact/working.

I know the green wire isn't for the tanks, but if it's for lockup that intrigues me.

Fuel Schematic

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[foamypirate]

Oh cool! Does that bypass the vacuum switch then? I wonder if an '84 has that.

My 84' had it. I ended up using it as part of my 700R4/TBI lockup wiring, I think.

 

[bucket]

The 70's trucks had the standard tank on the passenger side. When the tank valve loses power in a 70's truck, it defaults to that passenger tank.

The 80's trucks have the standard tank on the driver's side. I don't know for sure which side the valve defaults to if power is lost.

 

[chengny]

Tank switching (and tank level indication) is manually accomplished and controlled only by the dash switch. There is no feedback or position sensing circuitry. You are the controller.

The switch is of the DPDT momentary contact design with a "neutral" - Normally Open - position in the middle.

Toggling the switch up or down applies power (and reverses the polarity) to the actuating coil which moves the valve plug in the associated direction. Power continues to be applied to the coil as long as the switch is held in. Releasing the button allows the switch to move back into the middle (normally open) position - it is spring loaded to return to that point.

Once released, the valve will then stay right there. Lined up to whichever tank it was last moved to - until the switch is pressed to the opposite position.

As a matter of fact, to be sure that the valve rotates completely, the owners manual states that when switching tanks it is advised to hold the tank select button in for at least 2 seconds.

 

[bucket]

Tank switching (and tank level indication) is manually accomplished and controlled only by the dash switch. There is no feedback or position sensing circuitry. You are the controller.

The switch is of the DPDT momentary contact design with a "neutral" - Normally Open - position in the middle.

Toggling the switch up or down applies power (and reverses the polarity) to the actuating coil which moves the valve plug in the associated direction. Power continues to be applied to the coil as long as the switch is held in. Releasing the button allows the switch to move back into the middle (normally open) position - it is spring loaded to return to that point.

Once released, the valve will then stay right there. Lined up to whichever tank it was last moved to - until the switch is pressed to the opposite position.

As a matter of fact, to be sure that the valve rotates completely, the owners manual states that when switching tanks it is advised to hold the tank select button in for at least 2 seconds.

The earlier trucks are setup differently. The switch valve is just a self-grounded solenoid that engages when it sees 12 volts from the dash switch. The dash switch is a simple rocker switch that stays in position after it is pushed.

 

[Boone83K10]

well I did press and hold the switch and nothing happened...tomorrow I will try to get my hand up there to remove the switch.

 

[HotRodPC]

On my mid 80's trucks I hold the switch for 3-5 seconds just to make sure the gate opened all the way.

 

[Boone83K10]

did that...

 

[HotRodPC]

Could be a bad switch, or bad valve. Then again even a bad wire is possible.

 

[Boone83K10]

well I don't think it is a bad dash switch. contacts were all clean and everything..I cleaned the ground on the tank as well. I guess I need to probe the selector valve and then the sending unit in the tank.

I also have a question. There are 4 wires at the back of the switch, LT Green DK green are on top, Pink/Black and Pink/White on bottom. That fuel schematic shows LT Green and DK green and Pink for Hot and Black for ground. Why do I have a Pink/Blk and Pink/Wht wire? NEVERMIND THOSE ARE THE RIGHT WIRES... SEE BELOW FOR NEXT QUESTION!