Hot Rods fuel gauge problems

Hi Guys I am having a problem with my fuel gauge. Its a stewart warner fuel gauge. My power lead shows 12 volts. When i check for 12 volts going to the fuel sending unit no power to the sending unit.I have good grounds. The ohms on this gauge is 240-33. I am not sure on what sending unit it have. Would that cause the gauge reading empty. thinking about getting a 0-90 ohm gauge Any help would help

 

The sending unit doesn't have 12v going to it.

It's a resistance ground from the sending unit going to the gauge. Depending on how much gas is in the tank the resistance varies and the gauge reads it.

Make sure your gas tank is grounded or add a ground wire from the frame to one of the sender mounting screws.

 

The sending unit should have a ground wire on it.

 

I have a ground from the sending to the frame. I even ran a jumper wire from the sending unit to the frame. Should my test light get power when my key is in the run postion and it touchs the gauge post to the sender? To me you should get power on the gauge post coming out of the gauge also

 

Dreddybear ( Iirc) did a really good tech on guages and using potentiometers to ring them out, diagnose, and determine needed senders.

 

No.

Take the sender wire off of the gauge. Turn the ignition on. The gauge should read empty. Now touch a jumper wire that's attached to ground to the sender post. The gauge needle should sweep to above full. If not, the gauge is faulty (or not grounded). If it does the sender is faulty (or not grounded)

 

[QUOTEThanks="mashed, post: 10526848, member: 165943"]No.

Take the sender wire off of the gauge. Turn the ignition on. The gauge should read empty. Now touch a jumper wire that's attached to ground to the sender post. The gauge needle should sweep to above full. If not, the gauge is faulty (or not grounded). If it does the sender is faulty (or not grounded)[/QUOTE]