Fuel gauge reads too high.

[vince1]

I recall putting the ohm meter across the resistor and not getting the 85 to 90 ohms reading. It was in the seventies range if I was reading it correctly. The resistor is just one of those round ones with the coloured bands on it and wires coming out of the ends.

Reading over the post again and RustyPile's comment about the possibility of the resistor value changing tells me the gauge may not be quite as it should. I'll see how it works as the fuel level in the tank runs down. Perhaps I'll be taking it apart again to change that resistor.

[RustyPile]

Originally Posted by vince1

I recall putting the ohm meter across the resistor and not getting the 85 to 90 ohms reading. It was in the seventies range if I was reading it correctly. The resistor is just one of those round ones with the coloured bands on it and wires coming out of the ends.

Reading over the post again and RustyPile's comment about the possibility of the resistor value changing tells me the gauge may not be quite as it should. I'll see how it works as the fuel level in the tank runs down. Perhaps I'll be taking it apart again to change that resistor.

Those color bands indicate the value and % of accuracy of the resistor. It's physical size indicates the power rating. A flame proof, 85 - 90 ohm, 2 watt resistor is a perfectly acceptable replacement. These resistors can be obtained from any electronics supplier.. Grangers, Mouser, and Digi key are sources I use.

As I stated in my post, you CANNOT test the resistor when it is still attached to the gauge. You must remove it for testing.. The gauge has "built-in" resistance that combines with the external resistance and will give a false reading when using your procedure.. Remove the resistor for checking.. Replace the resistor only if necessary..

Just arbitrarily replacing parts and/or guessing are the worst ways to diagnose a problem.. Use good and proper methods as I have described and you'll solve your problem.

Since you have removed the needle, here's one way to install it properly.. Disconnect the gauge wire at the tank sending unit. Obtain a 45 ohm resistor similar to the one on your gauge. Attach the 45 ohm resistor to the end of the gauge wire and short the resistor to a good ground.. Turn on the ignition switch. If the gauge reads exactly 1/2 tank, the needle is in the correct position.. If not, remove the needle and reposition it to indicate exactly 1/2 tank..

Also, as I stated, where the needle comes to rest when the ignition switch is off is totally irrelevant. It can stop in any position or even remain at its last reading.. Don't clutter and/or confuse your mind (or this thread) with where it stops when the key is turned off..