The Stovebolt Site Forums The Shop Area Interiors Grounding Gas Tank?

There is a thread running on gas tank sending unit function. In that thread there are multiple references to grounding the sending unit. I didn’t want to hijack that thread , so here I am.

My sending unit does not have a ground wire. I was thinking that it probably grounded through contact of tank to cab, but in the course of installing my new tank I padded all the contact points. I thought I might have lost the ground contact- but I poured 5 gallons into the tank today and the gauge read 1/4 , so function checks.

Here’s my question:
Should that tank be grounded , sending unit function aside?
Should I be installing a ground wire to avoid static buildup, that sort of thing? If so , can I attach at a sending unit fastener?

Input , please.

By grounding the sending unit you are grounding the tank. The screws will ground the tank. Mine has a short jumper from the sending unit screw to the stiffening support on the back of the cab.

Ok , that’s a good way to ground the tank.
But does the tank need to be grounded? Is that a standard procedure?

The gauge needs to have a clean ground. (On edit, I really did mean to type sending unit, not gauge)

My 54 has a ground wire like Phil described and it looked factory if someone has a 54 wire diagram maybe it can be confirmed.

It seems that there is nothing to lose by grounding the tank.
Grounding the tank will also ground the sending unit (which is working fine as …)

I’ll ground my new tank on Monday.

My '57 is grounded at one of the sending unit screws to the rear of the cab.

I will do something similar.

What Buckshot says... my 54 3100 is factory grounded like that.

Grounding the tank is also a good idea for disipation of static electricity. On modern vehicles they have a ground wire from the fuel filler for that reason.

As I mentioned earlier, I used a soft interface at all the metal to metal hard points when I installed the new tank, so I may have lost ground contact. A good reason to take the easy precaution of grounding the tank.

Now, one might wonder why my sending unit and fuel gauge are functioning well without any apparent ground, but I guess I shouldn’t question success.
Which brings us to –- I dragged my feet on the grounding issue because the fuel gauge system is working as is. One might say that I am about to fix something that ain’t broke……

Gas tanks should be grounded, and I will ground mine. I just hope that my sending unit doesn’t take that as an insult.

The body of the tank was never designed to be grounded.
The sending unit was designed to be grounded via a ground wire which has a ring connector which goes under one of the sending unit screws. The other end of that wire goes straight down in front of the tank, through the floor, then forward to a nut and bolt which holds a wire strap. That end goes under that wire strap to be in direct contact with the cab. This nut and bolt is located under the driver seat.

That wire grounds the gas tank as well as the sending unit. Unless you're using non-conductive screws to hold the sending unit to the tank.

In your mind, does it somehow seem necessary to ground a gas tank?
The OP expressed that it was necessary to ground his tank. I had horrible thoughts of him drilling a hole in his tank for a ground strap.
That is why I clarified the sole purpose of the ground under a sending unit hold down screw was to ground the sending unit.

It's always been my belief and observation that early trucks had no ground wire to sender. They relied on ground contact thru sender screws to tank and tank touching frame. So when someone had trouble, we advised to add a ground from screw head to frame. Later years there was a tab on the sender for a ground wire. I don't know what Chevy "engineers" thought when sender has a gasket and tank had cushions under tank straps. I do not know exactly what AD had or did. My experience is 55.2-66 and up. The steel gas line would possibly ground the sender on it's way to fuel pump, at a line clamp somewhere, but it had a rubber hose near outlet.

Bottom line: Waveski's question is a trick question
Yes, the tank needs to be grounded to ground the sender. Other than that, no it does not. As everyone knows, the tank is hard to ground and maintain todays good idea to re-pad the straps/add cushions/whatever. The sender itself has a gasket. Small screws are not a super way to ground. Hence the newer truck's senders have a dedicated tab built in. So if you don't want to have trouble, ground the sender flange by adding a wire from a screw to the frame and don't ask questions. (second smilley face is non binding)

This is what Carl said in a much more friendly way and a lot less words.... and a lot less coffee.

Hey Carl -
Give me half a break here. Do you really think I’d take a drill to my new gas tank- the tank that is my reward for holding firm with Spectra Premium for over a month as they passed me off from one person to the next, even putting a technician on the phone who barely spoke English?

What the Helios???

My sending unit works just fine as is. Maybe I’ll ground it, maybe I won’t. Forget that I asked.
This thread has run its course.

Imagine a smiley face here if you wish. I don’t use emojis.

Waveski,
We're good Wave. My concern was not directed at you specifically. There are a lot of newbies who wind up in here and I was just trying to clarify how the senders were grounded originally.

Bartamos, ole pal. The ring connector for the ground wire is held down by a small sending unit screw, but that ring connector makes very good contact with the top of the sending unit which is all that is needed to make it work.
If one were to use a sturdy screw which did not conduct electricity whatsoever, the ring connector would still be securely grounded to the top of the sending unit, would it not?

I am going to throw another monkey wrench into this discussion.
The original tanks were not painted, nor were the tank straps.
Given this, the tank would have been grounded in effect.
So why did they add a ground wire under a sending unit screws on one end while the other end of the ground wire was placed under the cab, under a preexisting nut and bolt which held a wire clamp.
Maybe they had issues with the tanks remaining grounded early on and this ground wire was a bandaid fix implemented an all trucks from that point forward.
It would not be the first odd bandaid fix implemented on AD trucks through the long run of production.

Carl I know you try hard to conflict with me but you are not up to it today. Ole pal

Allow me to explain my comments.

1. Screw comment had nothing to do with screw and ring tongue being a good ground. That's why I said that we always suggest that. I am probably one of the first, if not THE first, to suggest that way back. It's a direct wire from flange to frame using the screw head as a clamp.

2. The comment was made about the original method of grounding the flange which has an "insulator" gasket. So the ground path was thru small screw threads into tank. I said "not a "super" way to ground." Meaning you should NOT rely on just screw thread for a ground. The tank, painted or not, had "insulator" pads under the straps on vehicles I've had. This underscores why so many folks post about gas gauges. Something was wrong with the initial factory idea or it did not last. Good ground is extra crucial in the way the rheostat and gauge work together.

3. I also said "I do not know exactly what AD had or did. My experience is 55.2-66 and up."

4. I did not know they added "a ground wire under a sending unit screws on one end while the other end of the ground wire was placed under the cab, under a preexisting nut and bolt which held a wire clamp." as you say. I don't know who "they" are. So I can't answer that for you.

5. Peggy has asked several times the past month NOT to quote, using quote.

Let's don't prolong this simple issue for no reason. I tried to complement and be kind to you in my post and use a touch of humor to Waveski. TWO emogeees! Geees boys.

As Waveski put it,I agree and I’m closing it to any more conversations.