when i start up the engine sometimes the gauges do not work but when i bang on top of the dashboard the gauges come back on
The problem can come from a few areas depending on the vehicle. It can be a loose ground to the instrument cluster, or a circuit board failure inside the cluster itself. Some vehicles also use an amplifier in the cluster to signal each gauge properly. You can try removing the instrument cluster harness connector, checking for any looseness, and reconnecting it. If there are no apparent loose connections, then the gauge cluster may have to be sent out for repair.
Have a car question? Get free advice from our top-rated mechanics.