VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt fuel gage reads full

Hi; On my 52 chevy my fuel gage alwayss reads full.I put a new tank in as well, as a new sending unit and the same thing happens.any idears. The old tank and gage did the same thing. Thank you

...you say "always"...But does that mean when the key is turned off , too...?

The fuel gage goes to full when you turn the key on,when key is off the gage goes to empty sorry I did not put that in.any help . thanks

Have you switched the car from 6 to 12 volt?

Have you checked to be sure the sending unit float Is not hung up or stuck In the up (full position )?
Richard

Have you tried replacing the gas gauge with another unit to see if it does the same thing?

Have you checked the ground for the tank and the wires going from the tank to the gauge unit?

Sounds like you have an open circuit. When the sending unit float is in the full position the rheostat is at full resistance. If you pull the sending unit and use a multi-meter you should show ~30 ohms resistance in the full position and ~0 in the empty position. If the sending unit checks out good it's likely a break in a wire or other bad connection. A break in a wire or a bad connection is the same as full resistance in the sending unit, your gauge will display full.

This is a new gage that I just put in as well as a new tank. The car is the orignal 6 volt ,does the tank need to be grounded whith a separate wire? the old tank and new one had no other wire on it. Where would I put the ground wire to ,body or frame.Thank you. This problem was whith the car when I got it,and I know the fellow before me had the tank out to clean it,and he could not get it to work

If the gauge goes past full then it is not grounded, I would run a ground wire from the sending unit to the body or frame. A quick check you can unhook the wire at the sending unit and ground it and the gauge should reed empty with the key on.

...It's not a bad idea to add a ground wire while things are apart...slip a wire connecter under a sending unit screw and I run it to the tank strap bolt ( use a large loop connecter ) no holes to drill , etc .
...Sounds like you may have to run a new wire , gauge to sending unit...if your sure that last guy didn't wire the gauge backwards...! Good Luck , Kevin
...Is this a Truck or Car...?

Hi there,
A point not mentioned is that you are messing about with electricity and petrol, and possible an open tank to check the sending unit.
Always DISCONNECT the battery, you dont want even one spark in that area..........

Just a thought
Peter

Very common ... run a new line from dash gauge to sending unit. IN THIS MANNER, YOU'RE NOT LOOKING FOR BREAKS, CRACKS, ETC.

Thanks,for all the replys.After burning out a new fuel tank sending unit,I found that some one wired the ignation wire to the the sending unit side.Put it right and a 2nd sending in ,and now it is working. Thanks again