I started tonight by trying to figure out why my fuel gauge only went to half full at best... Decided to finally swap in my good, used sender and see what happened. It went from reading a 1/4 tank to a half tank. It's a start right?

So I grounded the green wire (at the gauge) and the gauge read full. Good I thought to myself... So I thought I might have a bad ground somewhere. I jumpered the gauges ground wire to a new ground and no difference was made.

Then I decided to clean the big ground cluster under the fuse panel, mostly for the hell of it. Found it loose and a bit corroded. Cleaned it up and tightened it. No difference in anything...

I then removed the ground and started turning things on. I was certain I would find something that didn't work, but I didn't...

Figured tomorrow I'd go through the pain of getting to the sender (fuel) again and grounding the green wire out there to see if the gauge reads full, but what on earth does that big bundle of grounds actually do under the fuse panel?

Signals
Hazards
Headlights
Dash Lighes
...all seem to work.

It's not uncommon to have other common ground from previose repairs or installs. Say I install a set of aftermarket foglights that are designed to ground through the mount and I run the brown ground to the mounting bolt. I just created another common path to ground . Yes green wire to ground the gauge should read full but that does not mean the green wire is not damaged and has more resistance than a 100% good wire. So you may need to replace the green wire. The sending units seem to all read differant do to dirt and wear. Only trust the red light.

Steve

Try this, remove the sending unit with the wires attatched. Wit the up ( wires on top) the gas gauge should read empty and the gas light should come on. Now turn
the unit over the gas gauge should read full. If not check the ground on the drivers side on the car in the trunk. ( Brown wires)

Hope this helps

Sure does. I'll try it tonight.

Thanks.

Cleaned up the grounds at the head lights and tried both of my senders. Both work just fine out of the tank, but with close to a full tank and the sender installed I still only get 1/4 to 1/2 a tank registered at the gauge. I tried raping on the sender with a rubber mallet to see if the float might be sticking, but it did nothing... Float seems to work smoothly when I turn it upside down/right side up out side of the car.

Stumped...

Did the light come on in the gas gauge when it was out of the car and the needle showed below empty?

yup... Light worked. Everything worked when it was out of the tank.

Sounds like the float is sticking, take your spare sending unit and remove the nut
on the bottom and take the cover off. Check the chrome center shaft for pitting or
rust in your case it should be half way up. If its dirty clean it with a brillo pad.
BE CARFULL don't break any of the wires!!!! But it back together and try it in your car.

The spare sender that had the same affliction was fairly shiny and no rust. It had a fine film on the chrome center shaft at worst... That was about the 4th time I had it apart and the copper ground wire finally broke. Oh well... I kept it for parts.

Any other ideas? I hesitate to buy a new sender.

I did manage to fix the turn signals with a new hazard relay!!!