Fuel gauge ground!?

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GermzD74

GermzD74

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The gas gauge aint working...im considering it might be the ground I've herd around...

Well here is a picture of it...there is the sender hose with the rubber hose and one clamp and a metal long clip which im guessing is the ground...and then there is the wire next to the outlet.

Well I have no idea how it is being grouded by that clip...is there something missing here? does that clip need to touch a ground on the actuall car? or touch the clamp on the rubber hose? or is it fine as is...just needs cleaning?

IMAGE_322.jpg
 
the entire car is ground (chassis ground). That ground strap serves as a jumper wire over the rubber fuel hose which interupts the ground continuity yo the sender. If not for the rubber seal between sender and tank theu wouldn't need that strap. Hope this makes some sense. Just scrub the ground strap around a little to make a clean metal to metal contact at both ends.
 
while your under there you should take a stab light and check the hot wire with the key on there should be a pulsing hot at that wire if there isnt ive usually had to replace the fuel gauge but it could also be open between the gauge and the sender if you have a pulsing hot there and the ground doesnt take care of it you need to pull the sender out ive only run into two problems at that point most common for me is a bad sender but i have also had a couple bad floats that were full of fuel and always read empty good luck with the fix Justin
 
i kind of have the same problem, mine doesnt work sometimes. You have a full tank one minute, empty the next.
 
Mine worked once in the rain and never worked on a dry day in the 71 swinger.

I do not have the ground strap.

I was thinking possibly that the water completed a ground path because once the roads dried up, the fuel gauge quit working all of a sudden.

I hate intermittent problems.
 
take a jumper wire, pull the wire boot offf the sender, jump the sending unit wire to ground, turn the key to on and see if the gauge pegs to or past full. if so, its the sending unit, if no reading, its the gauge.
 
In the absence of that clip on jumper, you can run a jumper wire from one of the screws on the tank body (_NOT_ the gauge connection) to any convenient point on the chassis or body. With the clip-on jumper, clean the clips and the metal where the clips connect, and maybe just tighten up the clips a bit. The clip jumper just completes the ground circuit from the tank to the metal fuel line. The metal tank body just has to be grounded. HOW isn't really important.

BC
 
Hmmmm well like some of you here, the California rain seemed to help me diagnose the problem. #he gauge works. But that's probably going to end once the car dries.

What im guessing is that in order for the gauge to work, the actual tank has to have good ground? Because the water is substituting as a ground supplier...I cleaned the ground clip on the sender...and before it rained it didn't help...so...what do I do? grown one of the tanks screws with he chasis?

BTW: we are no longer dealing with the 67 valiant on my avatar...I am now a proud parent of my fav. car so far...68 Dodge Dart GT! (gts being my actual fav.)

I will post pictures once I get internet on my comp.

I still can't believe I own my dart!!! lol
 
A lot of the problems with gas gauges is related to the "constant voltage regulator" . It is a small relay like devise the plugs into the back of the instrument cluster. You might try a new one of them if the grounding is not the answer to your problem.
 
440Ken said:
A lot of the problems with gas gauges is related to the "constant voltage regulator" . It is a small relay like devise the plugs into the back of the instrument cluster. You might try a new one of them if the grounding is not the answer to your problem.
Click to expand...

click this link for info on the INSTRUMENT voltage regulator:

http://www.allpar.com/history/mopar/electrical2.html

Lots of other instrument related stuff, too.

BC
 
FWIW, this may not be relevant, but I have an an old D100 pickup and if the ignition switch doesn't return far enough after it's started the fuel gauge won't work. Turning it back (as if to turn it off) a little bit is enough to get the gauge working again. Instrument power is routed through the switch.
 
Chassis ground is a metal to metal path. Like everything metal becomes wire. That probably dont make sense to some of you either. Anyway...
The gas tank probably is chassis grounded given how it is straped in. The fuel sender is isolated by rubber both by the fuel hose and by the sender seal. The factorys little ground strap is a simple way to complete the chassis grond from the sender to everyhing else chassis. The metal fuel line is chassis grounded by all those hangers along the fuel rail.
Now if we hunt another place where the chassis ground could be broken we find ourselves back at the chassis to engine ground strap to the firewall. That has to be in place to complete the chassis ground side of the circuit across the engine to the ground cable and on to the battery. Am I helping at all ? I'm trying :)
Heres a quick test or fix to try... take any piece of wire (even coat hanger) and install a jumper from the battery ground post to the radiater support. Factory installed this same jumper on 73 and up models in addition to the firewall strap.
 
64ragtop said:
In the absence of that clip on jumper, you can run a jumper wire from one of the screws on the tank body (_NOT_ the gauge connection) to any convenient point on the chassis or body. With the clip-on jumper, clean the clips and the metal where the clips connect, and maybe just tighten up the clips a bit. The clip jumper just completes the ground circuit from the tank to the metal fuel line. The metal tank body just has to be grounded. HOW isn't really important.

BC
Click to expand...




My car has a ground strap from the tank to the frame. I've never seen one done like that but it's the way I bought it. Don't know if it's factory or not. But I would make sure you are getting a good ground from the tank to the frame.
 
The use with factory ground strap provides that the fuel line is grounded, if your fuel line is clamped with rubber clamps and using a rubber hose to connect to the fuel pump you wont have the sending unit grounded. Try with to ground the sending unit to a known ground, and test for results.
 
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