How do I bench test the fuel guage,chef-

on the sending unit connect an ohmmeter on the 0-100 ohm scale (the red lead +) to the terminal on the sending unit and connect the black lead(-)to a good ground connection to the base of the sending unit. The meter should swing from close to zero ohms to around 30 ohms when you move the arm up and down. if the meter only reads zero ohms regardles whether the arm is up or down the sending unit is shorted, and if the ohm meter doesn't move off of the high end of the meter the sending unit coil is open, if the meter reads 30 (aproximately)ohms whether the arm is up or down the arm isn't changeing the resistor value. To bench test the complete unit connect the terminal to the sending unit with a 10' piece of auto wire and connect the base of the sending unit to the base of the gauge (ground) and connect a hot lead from a 6 volt battery (+) to the gauge hot terminal and a ground wire from the battery (-) to the base of the gauge and also to the base of the sending unit.when you move the arm through it's arc should move the gauge from E to F. I have checked the sending unit in dash by grounding the wire going to the sending unit and opening it and the hand should flop from E to F when the switch is on and you have voltage to the terminal on the gauge. I don't like to have the lead shorted for any length of time, it may damage the gauge. I hope this helps, maybe someone else has a better way to bench test. If you are used to using a Volt ohm meter to check simple DC series circuits this is a good way, if not maybe one of your electronic repair tech friends or a mechanic will check the gauge out for you.

here is a link to the 49 -53 shop manual section on instruments and gauges. 49-53 shop manual section 12

I test gasoline gauges the same way, but I use a battery eliminator instead of a battery.

Thanks JunkYardDog, I was editing while you were typeing...

Thanks guys,the existing gauge in the dash doesn't seem to work and I've done several tests.Before I replace the sender I do have another gauge but don't remember if it works,will give it a try,chef-

Post deleted by lens49

chef chevy
Did you find the problem on the fuel gage. I had a problem on my 49 and thought it was the sending unit. I bought a new sending unit from chevy of the 40's, but never used it since i found the problem in the wiring. If you need a sending unit i will offer it for way less than the chevy of the 40's sell it for. i also have the tank and vent hose (new) Lens49 my email is kmsr1006earthlink