Author Topic: tank switch/valve  (Read 12621 times)

Offline Boone83K10

  • Registered Users
  • *
  • Posts: 159
Re: tank switch/valve
« Reply #15 on: May 10, 2013, 10:21:56 AM »
That is not how my truck looks. I just redid the entire dual tank setup.

My switch has 4 wires coming off the dash switch.

Pink/White for hot that goes to IGN on the fuse block.
Pink/Black for ground that goes to the buss bar on the parking brake.
DK Green for Right tank
LT Green for Left Tank

the DK Green and LT Green go through the firewall by themselves. They come out between the brake booster and the cruise servo.

I do not have a BLUE wire at all. Here is the schematic I used to redo my dual setup.





That connector almost looks like the high beam switch that is in the floor. That connector DOES have a BLUE wire so I don't know who fudged that whole setup.
« Last Edit: May 10, 2013, 02:14:26 PM by Boone83K10 »
1966 Mercury Comet - Built 429 (First Car/Show Car)
1983 Chevrolet K10 - Built 350 (Winter Toy)
1992 Chevrolet Lumina Euro (Sold @ 265,000 miles)
2003 Ford Escape 4x4 - Mac Perf. Intake/Exhaust (Wifes' DD)
2007 Mercury Milan - Steeda Tuned (Summer Toy)

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: tank switch/valve
« Reply #16 on: May 11, 2013, 12:53:08 PM »
The dash switch has 5 wires coming off it, the dark green goes to the unknown connector,  the pink with white stripe, light green, blue, and pink go through the firewall like its supposed to, the only thing is instead of a pink  with black stripe wire going from the fuse block to the dash switch,  it goes to the connector and a dark green wire goes the dash switch. The connector seems factory in the way it attaches to the side of the fuse block.

It seems that ignition power for the selector valve should arrive to the dash switch via the 'dark green' wire coming from the 'mystery connector' on the fuse block.  Post a pic of the backside of the connector plugged onto the dash switch that clearly shows which wires enter which cavities.  I want to verify switch wiring before making a recommendation.  My guess at the moment is similar to yours... there's a module/relay missing from the 'mystery connector,' but I'm missing the logic for two power sources to it....
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: tank switch/valve
« Reply #17 on: May 11, 2013, 01:26:24 PM »
Perusing service literature to find additional info, if possible....
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline rich weyand

  • Senior Member
  • ****
  • Posts: 1391
Re: tank switch/valve
« Reply #18 on: May 11, 2013, 02:28:42 PM »
Boone83K10: From that wiring diagram, you have the motorized tank selector valve, where the two leads to the selector valve reverse + and - to switch tanks.  I think the solenoid tank selector valve, with a single lead to the selector valve and a frame ground, is what he probably has.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Rip

  • Newbie
  • Posts: 28
  • Newbie
Re: tank switch/valve
« Reply #19 on: May 11, 2013, 06:53:14 PM »
Hope this is clear. The side with 3 wires is from the top, blue, pink, and pink with white. The side with 2 wires is from the top, light green, and dark green. This is the connector at the back of the dash switch. This view is through the  hole in the dash with the plug turned around to show the back. I cant figure what would need two hot leads either. I think i heard something about a timer that would keep a system pressurized after the power was shut off to help avoid vapor lock, but cant remember what years or models it was used on, or where i heard that. I think i could bypass the  unknown connector to put power to the dark green to feed the valve through the light green, but i dont really want to alter it. Its a california truck if that would help.

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: tank switch/valve
« Reply #20 on: May 11, 2013, 07:38:07 PM »
The dark green wire connects to ignition through the 'mystery relay/module.'  I'm unable to find any reference to the missing component.  I'll keep my eyes open and post here if something turns up.  To make it work (temporarily) and check the function of the selector valve, jumper fused ignition to the dark green.

What color wires plug into the two terminals at the top of the 'mystery connector and have you figured out where they connect?'  The timer module to which you refer is used on later TBI vehicles with electric fuel pumps.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline rich weyand

  • Senior Member
  • ****
  • Posts: 1391
Re: tank switch/valve
« Reply #21 on: May 11, 2013, 07:48:49 PM »
The wire colors don't match, but the right circuit diagram for what you have is probably the one toward the bottom of this page: http://67-72chevytrucks.com/vboard/showthread.php?t=558564

In that case, dark green is definitely the hot from the ignition socket on the fusebox, light green goes to the solenoid valve, the two outer wires on the other side (light pink, light blue) are the sender unit wires from the tanks, and the center (darker pink or red) wire is to the gauge.

Voltmeter checking should show: dark green wire hot all the time, light green wire either hot or open depending on the switch, light blue and hot pink wire should be to ground through a resistor with a value between 0 and 90 ohms depending on fuel level, and the center dark pink/red wire should read hot from the gauge.  Grounding the hot pink/red wire should send the gauge to EMPTY.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Rip

  • Newbie
  • Posts: 28
  • Newbie
Re: tank switch/valve
« Reply #22 on: May 11, 2013, 10:52:02 PM »
bd- into the mystery connector is the dark green wire that goes to the switch, pink with white from the fuse block, orange from the fuse block, and a black ground that junctions with other black grounds in a connector behind the dash.

Offline Boone83K10

  • Registered Users
  • *
  • Posts: 159
Re: tank switch/valve
« Reply #23 on: May 13, 2013, 12:52:08 PM »
this should help some...
« Last Edit: May 13, 2013, 12:55:22 PM by Boone83K10 »
1966 Mercury Comet - Built 429 (First Car/Show Car)
1983 Chevrolet K10 - Built 350 (Winter Toy)
1992 Chevrolet Lumina Euro (Sold @ 265,000 miles)
2003 Ford Escape 4x4 - Mac Perf. Intake/Exhaust (Wifes' DD)
2007 Mercury Milan - Steeda Tuned (Summer Toy)

Offline Rip

  • Newbie
  • Posts: 28
  • Newbie
Re: tank switch/valve
« Reply #24 on: May 16, 2013, 10:28:25 AM »
I had the valve bypassed and just the left tank hooked up, but now i put a jumper wire in the connector from the pink with black wire to the dark green wire and i have power to the valve. I havent put gas in the right tank yet but  i think it will work fine now. The gauge still goes past full on the left tank so i will have to check the wire to the tank for a break.Whatever plugs into the connector seems like it could do different things depending on how the wires are on the connector, since there is an unused terminal on the connector, like another ground for the orange wire from the fuse block, although i dont know why they would include the orange but not the  other black. I looked on the options list anf other than duel tanks and carb it doesnt list anything about the fuel system.

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: tank switch/valve
« Reply #25 on: May 16, 2013, 11:08:35 AM »
I'm supposing that ignition and ground provided the control to energize the relay/module, which then connected battery (org) to the dash switch (grn).  It will be very interesting if we're ever able to determine what they were trying to accomplish and why the extra complexity.

On the left tank showing past full, don't neglect the ground connection to frame from the sender.  You can check the sender by unplugging it from the circuit then connecting an ohmmeter between the sender signal wire and ground wire.  It should register somewhere in the range of 0 - 90 ohms.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Boone83K10

  • Registered Users
  • *
  • Posts: 159
Re: tank switch/valve
« Reply #26 on: May 16, 2013, 12:03:35 PM »
I had the valve bypassed and just the left tank hooked up, but now i put a jumper wire in the connector from the pink with black wire to the dark green wire and i have power to the valve. I havent put gas in the right tank yet but  i think it will work fine now. The gauge still goes past full on the left tank so i will have to check the wire to the tank for a break.Whatever plugs into the connector seems like it could do different things depending on how the wires are on the connector, since there is an unused terminal on the connector, like another ground for the orange wire from the fuse block, although i dont know why they would include the orange but not the  other black. I looked on the options list anf other than duel tanks and carb it doesnt list anything about the fuel system.

I think you need to forget about that connector. I think someone just used whatever they had laying around. I don't even know why they thought that "plug" would transfer power through because it has female ports. I don't get why there is a DK GRN wire because nothing on the schematic about that.  Why not just wire it up like the schematic I gave you.
« Last Edit: May 16, 2013, 12:15:58 PM by Boone83K10 »
1966 Mercury Comet - Built 429 (First Car/Show Car)
1983 Chevrolet K10 - Built 350 (Winter Toy)
1992 Chevrolet Lumina Euro (Sold @ 265,000 miles)
2003 Ford Escape 4x4 - Mac Perf. Intake/Exhaust (Wifes' DD)
2007 Mercury Milan - Steeda Tuned (Summer Toy)