Fuel gauge/sender

[tiger1dd]

Hi, I'm new, and need help with my fuel gauge/sender.

I recently put in a new sender, which works good, but the gauge BARELY moves. (i.e. Still on the lower part of the "E".)

I checked voltage across the gauge, which is 5.20V (Check.)
I checked sender-to-ground resistance at the IC- 45 Ohms (Check)

Now, that part that throws me off is that the gauge will also peg to to full when grounded...

I'm lost...

Any ideas?

Thanks,
Dave


(p.s. Also just found info from another thread that says it could be the ground at the sender.... how do I check/fix that?)

 

[golf4283]

Maybe the float has a hole in it and gas is getting in. Happened on my new sending unit. Take it out and try drowning it in water. If it takes in water there's your problem. Replace with a brass one if possible. That's what I did cause my plastic got the hole.

 

[2+2GT]

It is possible to calibrate the two together. The first thing you need to do is pull the sender, connect it to the lead wire and ground, and cycle through E-F, and observe the gauge.

 

[tiger1dd]

Yeah, the issue is definitely the gauge. I happened to have another sender in my trunk, the same model as I currently have in the tank. I used a multi-meter and got the (uninstalled) sender to 45 Ohms, the same as the one IN the tank. I taped it there, and connected it at the dash, and grounded.

The result of that was the same place as the other. That eliminates it being the sender. So,I then played with the gauge, hoping to calibrate it, the thing is, that now, with the tank 1/4 of the way full, it's moves to halfway or above....

Any ideas or instructions on the proper way to calibrate the gauges?

 

[2+2GT]

Do as I described above, with the sender removed from the tank, and the gauge removed from the cluster, but connected (I SAID it was a PITA). There are two holes on the back of the gauge, with little gear teeth showing. Use a small phillips or torx to adjust the position of F and E.

 

[tiger1dd]

Gotcha! I couldn't get it as close to the F as I would have liked, because that made the needle "stand up", but, it's much better than it had been, and with 3.5 gallons in the tank it's a little off of 1/4, so.... I'll take it!

That finishes that problem. I'm sure I can find more questions to bother everyone with, sometime in the future.

Thanks,
Dave

 

[66 Restomod]

Sounds like good news!

If you encounter the gauge back on "E" when the tank has fuel in it, the new float (brass or not) might have filled with fuel due to a manufacturing defect (i.e., small pinhole). I replaced two new repro brass floats for this problem.

But there's a Ford float available for $7, which is great news. And a Ford sock filter for $22 to replace the repro one that falls off the end of the sender fuel tube -- or it might actually dissolve in gas. That happened to me twice as well.

Here's some more info with pix if anyone ends up in this situation:

Restoration and Modification of a 1966 Mustang Restomod: Brand New Repro Parts, Part II: More Adventures in Head-Scratching