Skip the auto shop - Our mechanics make house calls

Q: Gas gauge not working

asked by on

Had alternator replaced for the third time in 4 /mos turns out was a loose wire ($900 later) gas gayge & heater gauge not working now!!! Im so sick of this im thinking of getting a diff vehicle....whats wrong now??? Mechanic said they werent working this morning either...not his problem i guess...what could it possibly be???
My car has an automatic transmission.

The gas "level" gauge relies on a sending unit in the fuel tank. You’ll want to first confirm that the fuse in the circuit is in place and has continuity. If there is no issue there, the sending unit is then tested (per Factory Service Manual specifications) and the circuit from the sending unit to the dash gauge is confirmed to be intact (i.e., no shorts or opens and working ground).

Finally, the dash gauge is tested. Usually the sending unit in the tank fails and/or the wiring in the circuit has a break. By heater gauge, I presume you are referring to the engine coolant temperature gauge.

A similar protocol is following, that is both component (in this case a sensor screwed into a coolant passageway on the engine head) and the wiring are tested until the fault is found. If the mechanic replaced the alternator, instead of correctly diagnosing a "loose" wire, it is unlikely he or she will be able to diagnose your new issues without comparable, or worse, problems. If you want to get a second opinion on the faulty gauge readings you are experiencing, YourMechanic does offer a diagnostic for non-working electrical components, such as for the dashboard gauges.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Gas gauge not working properly.

I would have a technician check the codes on the computer. It may help find the problem your having. The gas gauge not working could be the sending unit in the tank or the wiring going to the gauge. I...

Q: Sway bar links bad

The rear sway bar links may not be noticed they are bad unless you have weight in the back of the car or are making highway maneuvers like changing lanes. The links help to keep the rear of the car...

Q: Shakes when stopped

Shaking or vibration may be caused by many different things such as faulty spark plugs, poor fuel pressure or misfires. Other things such as a faulty idle air control valve may cause the engine idle to drop below the normal...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...