I have a gas gauge in my 1955 ford f100 that reads full. No matter what the gauge pegs full.i have taken the stock sender out of the tank and wired it to my ez wire 21 circuit harness. I tried to manually manipulate the float but nothing works. Is there something I’m doing wrong? I tried to see if there was some kind of bad connection. Any ideas?
thanks
jerry

 

It is a possibility that your gauge is making a ground contact before it gets to the sender, thus acting like you are getting a ground thru the sender. If this is the case, the ground would be coming after it goes thu the gauge. I am going to try and post my pictures of how I tested mine. To eliminate any EZ harness mix ups, try hooking it up with out goint tohru the harness. Just try to see if the gauge is working and the sender is working first

 

I had hooked up my fuel gauge to a full 12 volts before putting it into gauge panel. it worked it went to full. I placed extended wires from my harness to the sender unit. I moved the float arm various ways with the reading always full. Also I had a 1/8 tank reading on my gauge before all this and now it just goes to full. Im thinking sending unit.
Thanks
Jerry

 

You need to check your sending unit with an ohm meter. I don't recall the exact rating for Ford off the top of my head and there are several ohm ranges based on make, year and sometimes model and Fords are not the only thing I work on so I can't help you there but you need to find the specs and ohm the gauge sender.

 

Hi I am a little confused on ohm meter testing. so I take off the hot and ground wire off of the sender and put a probe on each? I think Ford is full is 17 ohms and empty is 78 ohms. But what ever way I move float there is no change in ohms. I am thinking of buying a matched fuel sender and gauge from Mid Fifty.
thsnks
Jerry

 

Yep remove both wires, and probe each contact on the sender. Just make sure you have your meter set correctly. If it is a 'multimeter' style unit, turn the dial to the correct setting in the ohm range, and be sure that the red wire is in the correct location. (look for the 'ohm' symbols). If that is correct, then yes it sounds like a bad sending unit. I haven't checked mid-fifty but I bought one from LMC for only 35 bucks.

Good luck!
-Pete

 

Hi Pete. Do you think it’s better to buy gauge and sender unit package from mid fifty?
thanks
jerry

 

hard to say without testing the gauge, but my bet is that the gauge is fine and you are just in need of the sending unit. If it were me, i'd buy the sender by itself.

 

Perhaps you need a 12 Volt to 6 Volt Reducer to make gauges work if they were originally 6 volt ,,but I am no expert by no means

 

I just did a ohm test in my fuel sender. No matter full half empty I alway got 4 ohms. On the factory sender 10 ohms is full 78 ohms is empty. So looks like I at least need a sender. I am running a 6 volt fuel gauge with a runts reducer. Well at least I know. I test so I just don’t throw parts at my truck.
thanks
jerry