Vintage Mustang Forums banner

1 - 3 of 3 Posts

0 Posts
Discussion Starter #1
I replaced the fuel sending unit yesterday and filled the tank this morning.

The guage still only reads half full.
There is a full tank?

What might cause that?



Atlanta, GA
65 I6 200 Coupe (Daily Driver)

Supporting Vendor
3,961 Posts
Take the wire off the sender and ground it. The gauge should read
full when you do that. If it doesn't the gauge is in trouble. If it does
then the brand new sender you put in isn't giving the gauge a good
reading. If you can (or want to) take the sender back out (more work!)
and ground the housing to the car. Have some one move the float
all the way to the top. It should read full. Move it to half way and so on.
The arm could of got bent or the stops for the float arm need the be
tweeked a little. Good Luck!

3,628 Posts
to check gauge without removing from car remove wire on sender unit and using an ohmmeter you should read either 10 or 80 ohms (i can not remember for sure but i believe 10 ohms is for full and 80 is for empty) from conn. on gas tank to ground. if you have unit out you can check it by connecting same ohmeter between output wire and metal of sending unit to the same values. also check continuous reading as you slide sending unit float from on end of of variable resistor to other end indicating no dead spots. if your original unit was still operating at all you only need to clean it up by removing case around resistor and using emery cloth clean it as well as contactor - i did mine a year ago and it still is working. it was a very well built unit and should last forever. BE VERY CAREFULL WITH SPARKS AROUND TANK -you can lose a lot of hair. the half scale reading could be caused by VR, bad gnd, or sending unit hanging up in tank. if other gauges read normal scratch VR as culprit.

<P ID="edit"><FONT SIZE=-1>Edited by BillScott on 04/02/01 02:49 PM (server time).</FONT></P>
1 - 3 of 3 Posts