all filled up "NOT"

[BryanP]

Hey guys , well to start off I have had several 80's style pickups over the years but have found a issue someone here may be able to help me with . Ok the problem I am having is the fuel gauge will read empty to just under a half tank after i fill it up, never over half a tank will it read, I have just replaced the sending unit in the tank with a new one but still reads the same it will move down as the fuel is used. does anyone of ya'll have any ideas were to go next .1981 chevy stepside ,THANKS

 

[drabo]

If all the connections are good then maybe look at the sending unit. Could be the wrong ohms 60ohm vs 90ohm. The arm on your float could be bent not allowing it to full raise.

 

[BryanP]

thanks for the reply i have just put a new sending unit in last week and the gage still has the same reading that it had before putting it in ,I mean the same no diff. at all the truck had sat for several years in a barn ,could the gage be whats wrong ? i just hate to keep buying everything when it could be something simple , if the ohms where diff. wouldnt i be getting a diff. reading than before. like i had said the fuel level will move from empty to just under a half a tank when i fill it up but will never read more than half.

 

[nerfherder78]

Could be that a resistor on the back of the gauge has gone bad: link

 

[BryanP]

Thanks I will check that out just tired of not knowing how much gas is still in there

 

[vwnate1]

Fuel Gauge Testing

First thing to do :

Disconnect the sender lead at the sender and ground it to the frame and this shoud drive the gauge head to empty .

I assume you've already made sure the tank to frame ground wire is still present ? it was gone missing (with much of the rest of the original wiring ) on my '76 GMC C2500 .

There needs to be cab to engine and frame to cab ground straps too here & there else you'll never have accurate gauges .

You can also remove the sender and connect it up , add a ground wire and manually flex the float from one extreme to the other to see if it's good or not .

 

[58Apache250]

thanks for the reply i have just put a new sending unit in last week and the gage still has the same reading that it had before putting it in ,I mean the same no diff. at all the truck had sat for several years in a barn ,could the gage be whats wrong ? i just hate to keep buying everything when it could be something simple , if the ohms where diff. wouldnt i be getting a diff. reading than before. like i had said the fuel level will move from empty to just under a half a tank when i fill it up but will never read more than half.

Replace the Gauge.