gas gauge 1939 tonner
 

what should be the voltage at the connection on sending unit with the wire disconnected?

Re: gas gauge 1939 tonner
 

On the connection itself? zero, it is a path to ground. The current flows from the gauge in the instrument panel to the sender to ground.

Re: gas gauge 1939 tonner
 

I installed new sending unit, gauge not showing anything truck has been sitting for 35 yr. don:t condition of gauge itself any ideas

Re: gas gauge 1939 tonner
 

Same old problem. Ford gauges use the "King-Seeley" system which works differently from most other systems. Most (probably all) replacement sending units are the resistance type and won't work well in Ford systems. Touching the wire to ground should make the gauge move. If it doesn't, either the gauge or the wire to it is bad. Try a jumper from the terminal on the gauge to ground. No action, the gauge is bad; if the gauge moves, the wire to the gauge is bad. Only touch the wire to ground for a short time or you will have other problems.

Re: gas gauge 1939 tonner
 

I assumed we were talking original here, see that is not the case! Still zero at the sender connection, but it will be a resistance unit.

Re: gas gauge 1939 tonner
 

He said the truck has been sitting 35 years. I don't see what is wrong with your original assumption.

Re: gas gauge 1939 tonner
 

Will this little pictorial help in checking your set up?

Re: gas gauge 1939 tonner
 

run a ground wire from one of the screws holding the gauge to the tank to a good clean location--grounded mine to the cab back wall with ign on, if you momentarily touch the gauge wire to this ground does the gauge on the dash work?

Re: gas gauge 1939 tonner
 

Should be positive ground for the 6 volt system on the Ford. Yes?