Fuel Tank Switch Troubleshooting

[joeymarkgraf]

Hey all, I'm new to the Old School pickup thing. I just got an 81 C-10, which came factory equipped with dual fuel tanks.

I've been scouring the net for 2 days now to find out how the dual tank switching system works, but I have found very little on it.

My problem is that mine doesn't work. I plan on testing the switch with a multimeter to see if it works, but in the mean time I could use a little input on how to troubleshoot this system. It seems like they left it out of my Hayes manual....

Any help or sources of information is greatly appreciated.

[boxrodz]

Originally Posted by joeymarkgraf

Hey all, I'm new to the Old School pickup thing. I just got an 81 C-10, which came factory equipped with dual fuel tanks.

I've been scouring the net for 2 days now to find out how the dual tank switching system works, but I have found very little on it.

My problem is that mine doesn't work. I plan on testing the switch with a multimeter to see if it works, but in the mean time I could use a little input on how to troubleshoot this system. It seems like they left it out of my Hayes manual....

Any help or sources of information is greatly appreciated.

Have you made any leeway on this?

Your problem may not lie with the switch, but mayby with the fuel tank valve selector. Here's a few links dealing with the fuel valve:

http://67-72chevytrucks.com/vboard/s...d.php?t=213992
http://67-72chevytrucks.com/vboard/s...d.php?t=207287
http://67-72chevytrucks.com/vboard/s...d.php?t=180143

If it is the switch, you can check the operation of it by checking its' four terminals. The black wire supplies the ground and the pink wire supplies the +12V source to the fuel tank selector valve (through the switch). With the position of the switch selected for the right tank, the light green wire is ground and the dark green wire is +12V. With the position of the switch selected for the left tank, the light green wire is +12V and the dark green wire is ground. These two wires feed the fuel tank selector valve and metering swtich.

[PHOENIX]

Here is a link to a problem I had with the switch valve itself.
http://67-72chevytrucks.com/vboard/s...d.php?t=201901
The link will show you the inside of the valve if you are interested.

[joeymarkgraf]

Thanks for the info!

It turns out that it was a loose wire behind the dash... I have devloped a new hatred of messy wiring, so thats my new task this week.


Merry Christmas!!

[magnethead]

Originally Posted by joeymarkgraf

Thanks for the info!

It turns out that it was a loose wire behind the dash... I have devloped a new hatred of messy wiring, so thats my new task this week.


Merry Christmas!!

have fun then. my underdash looks like a rats nest.


but it probably was at some point, so mute deal there.