How can I check my gas gauge?

September 1, 2012 | By Richard Prince

Question:

The gas gauge doesn’t work on my 1968 Dodge Polara. How do I see if it is the gauge or the float or if there is another electrical component in the fuse box or elsewhere that may be the cause of the problem?

Answer:

The fuel gauge electrical circuit is fused so the easiest thing to check is the condition of the fuse.

While it’s somewhat unusual for the gauge to fail it certainly is possible. The easiest way to check the function of the gauge is to temporarily plug in another one that you know works. You can do the same thing for the sending unit, which is more prone to failure than the gauge. This, of course, assumes that you can get your hands on working examples of the gauge and sending unit. Your car has a voltage regulator (voltage limiter) behind the dash and if this has gone bad it can impact the function of the gauge.

And, of course, don’t overlook the obvious—make sure the sending unit has a good ground and also make sure the wire from the sending unit to the dash is present and accounted for.