Different vehicles have different gauges, and some instrument panels are much more complicated than others.
But when the gauges in your car stop working, its not a situation you could safely ignore.
An individual gauge doesnt work.
One or more dashboard warning lights dont work.
The first step in diagnosing this issue is to identify the fuse associated with the instrument cluster or gauges.
The fuse should have power on both sides when the ignition key is turned on.
This usually requires removing the instrument cluster, which can be quite difficult and time-consuming in some vehicles.
What If the Indicator and Dash Lights Dont Work Either?
This assumes that you have already checked the gauges fuse and determined that its in good working order.
What If the Gauges Seem Erratic or the Needles Are Pegged?
Gauges that all read full all the time are usually due to a loose or bad ground.
What If Just One Gauge Doesnt Work?
Otherwise, youll have to take it to a mechanic.
Using your coolant temperature gauge as an example, the diagnostic procedure involves locating and disconnecting the sending unit.
With the ignition on, the gauge should register cold.
If you connect the sending unit wire to ground, the gauge should switch to read hot.
If the gauge moves as expected, you’ve got the option to suspect a bad sending unit.
The speedometer is physically coupled to the transmission via a cable in vehicles that use cables.
The cable is usually square on both ends or square on one end and slotted on the other.
When the cable breaks, the gauge may not move, or it may jerk a little intermittently.
In many cases, this also requires removing the instrument cluster itself.
In less common circumstances, the electronic control unit (ECU) could also be malfunctioning.
Using specialized testing equipment, they will also be able to test the speed sensor itself.
What If Its Dashboard Warning Lights That Dont Work?
If those things check out, the problem is usually a bad sending unit or wiring.
