Dropped tank for gas gauge

[cfan10]

OK, so this morning I decided I will not tolerate the gas gauge that doesn't/hasn't ever worked properly since I bought the truck.
After dropping the passenger side tank I realized there is no broken off purple wire coming off of the sender, had the sender installed in '10 I believe it still works fine but has no connection for the purple wire that's grounded on the frame, that's I'm told is what sends the signal to my gas gauge. I just want my gas gauge to work, I've brought about six or seven junkyard clusters over the years I was young and got taken advantage of by not so good shops/mechanic's. Gas gauge always went to like 3 o clock, way past full.

As always thanks in advance!

'84 c10 350/350 dual tanks, only using the passenger tank and it's hooked up to an external electric fuel pump.

[Dead Parrot]

Normal colors are pink wire to gauge and black wire to frame/ground.
3 o'clock = open circuit somewhere.
Dual tank switch can also be a source of open circuit. If original, it is about 35 years old and probably been hit by more then one knee.

[cfan10]

Purple wire grounded on top of frame...goes where?

[cfan10]

More...

[Bandit130]

Mine was always pegged at 3'oclock. New tank, hoses and sending unit then worked correctly. The sending unit on mine was bad.

[kipps]

First thing I would check while the fuel sending unit is out-- Connect an ohm meter between clean metal on top of the sender and the pink? wire from the sender. As you move the sender through its full sweep, you should see it smoothly go from nearly 0 ohms to approximately 90. If so, your sender is fine, and the problem is the wiring or the gauge.

[fordguy40]

Originally Posted by cfan10

Purple wire grounded on top of frame...goes where?

If I remember right, that wire should be attached to a tab on the sending unit near the retaining ring.

[dieseldawg142]

Originally Posted by Dead Parrot

3 o'clock = open circuit somewhere.

this...
had the same prob.
trace the pink wire back to the cab looking for any points of contact in the wire.
wire clamp had chafed my pink and sent it to 3 o'clock

[hatzie]

Originally Posted by cfan10

Purple wire grounded on top of frame...goes where?

Likely to the sender ring... There should be a 1/4" wide tang on the sender tank ring that the short ground wire plugs into.
Purple is not the original factory tank ground wire color but I bet that's what it is. OEM GM tank ground wire color is black.
That disconnected ground wire can and will cause the gauge to sit at 3:00.