So I received my unit the other day and I said let me see if the gauge will move before I drop the tank. The unit is new and the sending wire is new, so i put the lead to the unit and plugged it into the connector on in the trunk. I then took the ground and held it against the metal on the trunk floor (totally metal). I moved the float up and down (with the key turned to on position).........and nothing......still sitting at E!!!!

Was this a ideal test? What can i do not to rule out other things? Is there a test i can do on the wire in the trunk to see if its sending any voltage to the unit?

I know the gauge "should be" cause at one point it was sitting at almost "E" then after plugging an older sending unit wire to the old unit it moved to just E.

Any help at this point to get past my slump would be appreciated.

 

E means that it's connected but there's no resistance. Essentially, if you unplug your sender, it should go past full because that means it's "Infinite" resistance. (hard for the current to travel through the air to the ground).

I bench tested my sender, when i wagged it up and down the gauge went from empty to full.

What happens if you unplug the sender? (There is a tan wire in the trunk for this) If it still reads empty after you unplug it, that means that either

A) there is a short somewhere
b) your fuel gauge pod is bad.

 

To add to this.

0 ohm resistance = empty on your gauge

90 ohm resistance = full

more resistance = pegged past full

touching your wire to any ground = empty (no resistance)

run these tests and let us know

 

Tony this is interesting and Thank You fotr the info.I have a 66 Olds Cutlass.New Sending unit.But it is an Offshore brand.I get a reading when full at about 1/2 of the gauge travel.Right in the middle..As it emties I do get activity down to 1/4 of a tank.My question is this ..Can the float be adjusted ? I did notice the filter is not a Sock Type .But a Hard Cylinder style. Could I have that filter located above the baffle instead of below it.And would that give me the reading I am getting.
Thanks in advance
Ron Roth

 

Where did you buy the unit from? What's the part number? It could tentatively be the Erin part... ( I know that's not what you want to hear..)

 

So I tried removing the ground wire and checking the gauge no movement. Also removed the tan wire and also checking the gauge I still didn't get any movement. So the next thing I did was I pulled the gas gauge to see maybe if it was that. Behind the gauge is a wire that is not connected to anything but its not part of the gauge harness. The back of the gauge is pretty rusted and maybe not getting power could that happen? All of the bulbs in the gauge are OK but they don't lite up is that any indicator of a fuse not allowing power to the gauge. I'm out of ideas and puzzled to death.

 

missing a peg on your gage back ckt board? Those are used on the 68-69 also, and INFAMOUS for the pegs coming loose or breaking right off.

I'd remove that rust, refresh all those pegs, and then re-test it and PUT SOME SILICONE GREASE on the pegs so the connector can be removed and installed w/o destroying it.

I have done a few of those pegs and boards, and have a few tricks. Solder, fill the peg with a teensy bit of wire, mechanically support it with epoxy as needed, etc.

 

How does one remove rust from the board. I don't think the pegs a bad the all seem pretty stiff and stable.

 

I was able to take apart my gauge and i cleaned the rust off pretty good. While disconnected and cleaning it the needed went to about 1/2 a take. So i figured this would be a great set up to test it out. Once installed back in i too the sending unit in hand, connected tan wire, and touched the ground to some metal on the out side of the car. Immediately the gauge started to move to E and actually went a hair past E. So then I started lifting the float........and NOTHING. I don't think there is a short anywhere so I might have to get a new pod. Cause it has not moved anywhere close to FULL. Guess I'm now on the pod hunt

 

That orange wire is probably for the map light in the mirror that was not installed in your car.

That peg looks to be missing, but since this is a std cluster, it should be missing.

Use an ohm meter and measure from ground to the tan wire for the sender - let us know what you get.

Also make there the cluster itself is grounded well. The ground is made when the gauge is bolted in and makes contact with the metal plate at the screw hole. Make sure that plate is grounded, too!

 

you can try soldering at the pin to circuit board connection point, they often lose connection at that point. just don't solder up the pin, only solder the larger ring at the very bottom where it meets the circuit board.


bill