Fuel gauge issues - 65 Plymouth

[65_Satellite]

Ok guys, hoping you all can help me out. Im lost on this one. Heres what I got.
Ive run out of gas several times in my 65 Satellite cause the fuel gauge doesn't work. Decided to take a look and see what I can find.

The gauge reads empty with key or or key off so I pulled the wire off of the sender and ran a jumper lead direct from the negative battery terminal to the wire and the gauge pegged at full. This made me believe that it was a sender issue. So I pulled the sender and low and behold, the float had a hole in it and it was full of fuel. Ordered a new sender and installed it. Same issue and the gauge was still at empty. Grounded the wire and again it pegged to full. So now I started looking at grounds and decided to ground the tank directly to the body so I drilled a small hole in the corner lip of the tank and ran a ground strap the upper shock bolt. Fuel gauge still reads empty. Further looking around I realized that I replaced all my fuel line with braided line and the factory steel line was removed so the ground strap that jumps the steel line and the sending unit really wasn't doing anything so I ran a separate wire from the body to the sending unit as a ground. Same issue the gauge was reading empty. Decided to just buy an attometer fuel gauge just to have something. Gauge came in today and I went to start the car and when I turned the key on, the fuel gauge now pegged to full like it would do when I grounded the sending unit wire. What am I missing here and what should I be checking??

 

[493 Mike]

You should have cycled the tank sending unit with the key on and a witness watching the dash gauge before you installed the new sending unit. Just ground the removed unit with a jumper wire, with the factory connector plugged on the sender stud.
Mike

 

[65_Satellite]

You should have cycled the tank sending unit with the key on and a witness watching the dash gauge before you installed the new sending unit. Just ground the removed unit with a jumper wire, with the factory connector plugged on the sender stud.
Mike

I didn't think to cause it was brand new. Just installed it and put fuel in the tank. Its now in the tank and the sending unit itself is grounded to the chassis and the tank is grounded to the chassis. The wire is connected to the sending unit and the gauge reads past full

 

[Beekeeper]

Is the tank full? If so unhook the sender wire and using a multimeter check the resistance at the sending unit. Should be 10 ohms or so do that and report back your findings. It should be noted that the “new” sending units are linear and the original mopar are non linear so the gauge will never read exactly correct. The best thing you could do is send your original in for a rebuild.

 

[65_Satellite]

Is the tank full? If so unhook the sender wire and using a multimeter check the resistance at the sending unit. Should be 10 ohms or so do that and report back your findings.

I honestly don’t know how much is in the tank. If I was to guess maybe 7 or 8 gallons so maybe I’ll take it to the gas station and fill it up. It’s just odd that the gauge was always reading empty and now all of a sudden it’s pegged past full with the key on

 

[Beekeeper]

I honestly don’t know how much is in the tank. If I was to guess maybe 7 or 8 gallons so maybe I’ll take it to the gas station and fill it up. It’s just odd that the gauge was always reading empty and now all of a sudden it’s pegged past full with the key on

have you tried disconnecting the sending unit wire at the sender to see if the gauge still pegs full now? Also I added I bit more info on my post above

 

[justjim]

Ok guys, hoping you all can help me out. Im lost on this one. Heres what I got.
Ive run out of gas several times in my 65 Satellite cause the fuel gauge doesn't work. Decided to take a look and see what I can find.

The gauge reads empty with key or or key off so I pulled the wire off of the sender and ran a jumper lead direct from the negative battery terminal to the wire and the gauge pegged at full. This made me believe that it was a sender issue. So I pulled the sender and low and behold, the float had a hole in it and it was full of fuel. Ordered a new sender and installed it. Same issue and the gauge was still at empty. Grounded the wire and again it pegged to full. So now I started looking at grounds and decided to ground the tank directly to the body so I drilled a small hole in the corner lip of the tank and ran a ground strap the upper shock bolt. Fuel gauge still reads empty. Further looking around I realized that I replaced all my fuel line with braided line and the factory steel line was removed so the ground strap that jumps the steel line and the sending unit really wasn't doing anything so I ran a separate wire from the body to the sending unit as a ground. Same issue the gauge was reading empty. Decided to just buy an attometer fuel gauge just to have something. Gauge came in today and I went to start the car and when I turned the key on, the fuel gauge now pegged to full like it would do when I grounded the sending unit wire. What am I missing here and what should I be checking??

 

[justjim]

have you tried the voltage limiter ? gas gauge won't work with a bad one.

 

[65_Satellite]

have you tried disconnecting the sending unit wire at the sender to see if the gauge still pegs full now? Also I added I bit more info on my post above

I have not disconnected the wire again. I’ll try that. I didn’t know about the difference in the linear and non linear sending units and I actually threw away the original one cause I didn’t know they were rebuildable

 

[Darter6]

Not sure if the repops are adjustable.The OE ones are. If you remove the cover from the rheostat you will find the adjustment screw.
Then do the test that 493mike suggested .Adjust as needed.
Many many complaints with the repops not working or reading incorrect.

 

[66383]

Darter6 is right. Ask me how I know.

 

[hangn0ut]

Check your sender wire back up into the body. Moving it around working on this stuff could have caused a short. Insulation gets old and brittle and fails when moved. Whatever you find or not you know power is not going thru the resistor part of the sending unit. Instead it has found a ground. Might as well check from the gauge to the resistor part of the sending unit.