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Grounding a gas tank and a fuel gauge question

43K views 10 replies 7 participants last post by  docvette 
#1 ·
I have finally completed the body work on my 53 Ford F-100 and have now moved on to wiring it up. I purchased an American Autowire Highway 15 wiring kit that I am waiting for delivery on. I have began creating a "to-do" list and came about two questions:
1) I installed a "Tanks inc." poly fuel tank under the bed of the truck. I remember the installation instructions mentioning the need to ground the gas tank. How would I go about this. Would I use one of the screws on the fuel sending unit and ground it by attaching it to the frame.
2) Somewhat related to the first question I noticed that the fuel sending unit needs to be grounded. Would this be grounded separately near the fuel tank or does the ground wire get run up the fuel gauge on the dash and tied into the ground wire coming out of the gauge?

Thanks for your help. I am sure once my wiring kit arrives I will have several more questions.
 
#2 ·
If your sending unit is like mine, it only has one terminal and that is for the wire that goes to your gage. The sending unit is grounded through the flange that you bolt to the tank. That same flange (for the sending unit) also served as the tank ground on a poly tank. If it were mine I would run a separate ground wire from the tank sending unit flange to a known good ground point (not the frame).

Vince
 
#3 ·
The poly tank, because it's not metal, cannot be grounded.
The fuel level sending unit will usually have a control wire connected to the center terminal post. This wire is not connected to chassis ground but will run directly to the guage.
The fuel level sending unit will also have a ground wire connected to the chassis.
The fuel guage will have a 12 volt feed.
Follow the instructions you get with the kit.

vicrod
 
#6 ·
Thanks for the quick replies. The fuel sending unit that I have has two "prongs" on top. One is marked "ground" and the other is wired to the fuel gauge in the dash. Do I link the ground from the fuel sender on the tank to the ground on the gauge, or use two separate grounds, one for each? Sorry for the confusion.

As per the responses, am I correct in assuming that the tank is o.k. as is and does not need to be grounded?
 
#8 ·
Doc here, :pimp:

DO NOT tie both to ground!

The terminal marked "Ground" must go to a properly Bonded Ground buss , or Grounding area.

The Terminal marked "Gauge" albeit, REFERENCED to Ground..Is Not..It is the float position reporting signal from the tank..

Think of your system as a Volume Control on a Radio..The Gauge is the "Audio Sound" the Float is the "Volume Control Resistor" and ground is "Sound off",... no or high resistance to ground is "Full Volume"...

The gauge wire runs through a "movable float and resistor to reference a ground Back to the gauge to complete the circuit.

A poly tank can't really be grounded..you can go to anti static blankets and hardware , but that's about the extent of it.

Doc :pimp:
 
#11 ·
Doc here, :pimp:

Yup..kinda hard when you got a plastic tank though.. :sweat: :smash: :pain:

This is the way Traditionally , the system works..If the gauge reports backward swap the hard ground from the sender with the signal line from the sender..that SHOULD get it going the right way..(provided you have no other ground to the sender)



Doc :pimp:
 
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