How to test an analogue resistance gauge

Not sure if it's the sender or the gauge that has stopped working?

If an analogue gauge has failed, the needle will not travel from completely full to completely empty.

To test an analogue gauge, just disconnect the sender wire (usually black) and touch it to battery negative.  With the wire connected and disconnected you should see the needle travel from full to empty.  If it does this successfully, it is most like the sender that needs replacing.

 

To check to see what resistance the gauge is, follow these simple steps...

 

If you have access to the wires on the back of the gauge;

  • Power the gauge off
  • Disconnect the black wire (sender) 
  • Power the gauge on

  • If it's an American gauge the needle will show EMPTY
    • Touch the black wire to earth, the needle will go to FULL

  • If it's a European gauge the needle will show FULL
    • Touch the black wire to earth, the needle will go to EMPTY

 

If you don't have access to the back of the gauge;

  • Disconnect the two wires in the loom that attach to the sender.
  • Touch the two wires together (on gauge side of loom!)
    • If it's an American gauge the needle will show EMPTY
      • Touch the black wire to earth, the needle will go to FULL

    • If it's a European gauge the needle will show FULL
      • Touch the black wire to earth, the needle will go to EMPTY

 

To test the sender, click here