Someone Help me make my fuel guage work !

[Bullitt-]

I don't think your following the concept of the test we are suggesting. Unplug the wire to the sending unit & ground that wire to the frame & see if your fuel guage responds... should read very full.      Otherwise what you have in the Pic SB good.

[nivvy]

I did that it does read full.......

[Bullitt-]

I did that it does read full.......

This proves the wiring from the tank to the guage is OK therefore the problem is with the sending unit, either it is bad or not grounded.

[nivvy]

I tried using that bolt as a ground...the other wire is going to another part of the frame...

[Super Blue 72]

This proves the wiring from the tank to the guage is OK therefore the problem is with the sending unit, either it is bad or not grounded.

   Yep, I agree with bullitt.  That's the last (hopefully!) piece of the puzzle.  Have you check those 2 areas (bolt or frame where the sending unit ground wire goes) as known good grounds using a meter or other technique?

When you grounded the sending unit wire did you use either of those ground points (bolt or frame where the sending unit ground wire goes)?  If so and the meter went to full, then the grounds should be good and the sending unit should be tested.

[nivvy]

Ok I got my ohm guage...never used one before...so what do I set the ohm guage to (lots of numbers on there) and what do I ground on the sending unit?.................

[MEK-Dangerfield]

Ok I got my ohm guage...never used one before...so what do I set the ohm guage to (lots of numbers on there) and what do I ground on the sending unit?.................

If you are looking to measure your sending unit, the value will be less than 100 ohms if it is working. It will be infinite, if the sending unit is bad. New ones can be bad, by the way. Your ground would be someplace on the body. It would have to be clean(bare metal). No paint or rust. You would measure between that and the post that the sending unit signal wire is connected to.

  Mike

[nivvy]

Do I need the key turned or anything like that??

[71challengher]

Do I need the key turned or anything like that??

Well, yes

[MEK-Dangerfield]

Do I need the key turned or anything like that??

Not for this.  

OK, I have a new train of thought for testing your sending unit. Measure between the pick-up tube, and the post that the gas gauge wire goes to. That should tell us something. Use whatever scale will get you below 100 ohms.


  Mike

[71challengher]

Well, my key needs to be on for my fuel gauge to work

[nivvy]

I know the pickup tube isnt grounded because of the padded line clamps...

[MEK-Dangerfield]

Well, my key needs to be on for my fuel gauge to work

 I understand that Dear pain-in-the-butt, but we are measuring resistance of the sending unit at this point. No power needed. If the resistance is too high, the fuel gauge reads nothing with the key on.


   Mike

[MEK-Dangerfield]

I know the pickup tube isnt grounded because of the padded line clamps...

No problem there. We are measuring between the pick-up tube, and the, I believe it's called varyister of the sending unit.

 Stay with me here. 

[nivvy]

as you can see by the pic I have a pick up tube and a return line tube...does that matter?