Dual Tanks Switch Valve?

[discot315]

Hey I need some help from anyone who can help me, My 1980 K10 has dual tanks but it well always stay on the left tank even if I hit the switch to the right one... And the right ones FULL  left is almost empty... lol.  I heard a little while ago if I got someone to hit the switch while I was holding my hand on the switching valve I should feel it click or something?? I didnt so im guessing its the switching valve. I was getting some parts for my motor at NAPA (I live in Canada by the way) And I aws curious about it so I asked if they could order me in one and they said I would have to go to GM for that?

[discot315]

Just wondering if anyone has had the same kind of trouble and could give me some advice, or a place I could get a new switching valve thing. Thanks -Trevor

[Cody1018]

It could be the switch valve or the actual switch it self that isnt working. Ive had some trouble with my dual gas tanks as well. The gas gauge wont read. Even when i change it from side to side. The right gas tank is empty and when i change it to that it eventually dies. So i know the sending units and switch valve are working, but im not sure why it wont read fuel. Any ideas on what to do?

[78 Chevyrado]

If you have a voltmeter, have a friend help you do this test.

unplug the wire on the valve (I'm assuming your valve has a single wire like mine) and put a voltmeter between the wire and a ground, then have the helper switch the switch.  If it's like the one on my 78, you should have 12 volts when the switch is set to the left tank, and 0 volts when it is set to the right tank.

If you're not getting power, probably the switch needs to be taken apart and cleaned.  I haven't seen a bad switch yet, only dirty ones.   What the problem always is on the ones I have seen is that GM used a type of foam as a dust seal for the switch and when the foam goes bad it falls apart and gets on the contacts an blocks the electricity flow.    Just clean it out and put some non conductive grease in there and thats all there is to it.

If you do have power to the valve, unless theres a bad connection, the valve is bad.  You can try tapping on it, lightly (dot beat it up)  to see if it will free up, but once they quit, they're done.  

To get to the fuel in the full tank, just swap the hoses that go into the valve from the tanks, just remember thats what you have done.


Edit:  you posted before I got done typing...

If it wont read the fuel levels, theres a bad connection, bad ground, or shorted out wire somewhere in the lines.

[VileZambonie]

http://forum.73-87chevytrucks.com/smforum/index.php?topic=9072.0

[discot315]

Ok Thank you for the reply. I dont have access to a voltmeter yet so I didnt try that but im going to soon. And I took a look at the valve when I was there working on heater core and theres like 4 lines going into it, Im not sure what ones to switch over. I only took a quick look but im guessing each tank has 2 lines maybe the sending line and a return or something. Just sorta confused about which ones I would switch over to get to the fuel. Id love to have that full tank lol. Thanks

[VileZambonie]

I hate napa. If you have autozone near you or maybe they can cross reference it for you.

     SHOW COST  HIDE COST 
   
 Duralast / Fuel Tank Selector Valve
Part Number: FSV2 Warranty: Lifetime Warranty Notes:Universal
6 port motor driven; O.E.M. #12336291, U7001.
Requires fuel tank selector valve connector and
switch for proper installation.
 Store -0 Network -2 Hub -3          $111.58  $55.79 
   
 Duralast / Fuel Tank Selector Valve
Part Number: FSV1 Warranty: Lifetime Warranty Notes:Universal
6 port; O.E.M. #12336290, U7000.
Requires fuel tank selector valve connector and
switch for proper installation.
 Store -0 Network -2 Hub -1          $91.12  $45.56 

[1984k30]

I have not used my duel tanks in a while and tried them today.  Do you have to hold down on the button for 5 or so seconds to make it switch?

[VileZambonie]

You have to depress and hold the switch for a few seconds yes unless it's TBI

[1984k30]

Thanks I thought so.  Looks like I have a problem with mine too.  Will stick to left tank for now

[trink2030]

I have a couple of questions about the diagram if someone wouldn't mind explaining a little bit.

What are the two circles on the left side of the diagram with '53' and '54' in them?

What exactly does the 'Splice 53' and 'Splice 54 accomplish near the middle of the diagram?

Pumps and senders are cheap, I know the right tank hasn't been used in at least 5 years.  Good idea to pull it, clean it out and replace the pump and sender for good measure?  Both sides for preventative?

My plan is to fix it up a little at a time, starting with new leafs and brakes in the rear and working forward.  Just not trying to leave anything behind or forgotten.

Thanks for the advice

[beastie_3]

those two circles are connectors. they sandwich the firewall. one on one side, and one on the other side. the actual plug location on the firewall is between the distributor and brake booster.

I would just do one tank at a time if it is your daily driver. that way you still have one good tank.

[trink2030]

That's very helpful, thanks.  It's not my daily driver, just a weekend beater. 

[beastie_3]

id still do one at a time that way you have a reference as to what goes where.

[ctl_dog]

You have to depress and hold the switch for a few seconds yes unless it's TBI

hold it down? when I switch from left to right, the guage registers immediately, but your saying the reason the fuel doesnt flow, is because I'm not holding down the toggle switch for a few seconds?