testing electrical gauges

Some basic tests at the link.

• testing

I DO NOT recommend this but knew this dude (who was that guy and would do such a thuing lol) who would sort of crudely bench test them by ataching a hot battery lead wire to one terminal and then very briefly scratch/rub/touch/bump a wire from the other terminal to the other gauge terminal to see if the needle jumped over. It would be wise to have a current limiting resistor on one lead to prevent overcurrenting the gauge and popping/blowing it out, but as Bob pointed out one would need to know the senders ohms rating to run this test properly.

To work a gauge must have continuity through it and then its innards be okay so the needle deflects according to how much current flows through it. Typical problems may be internal corrosion has the needle stuck or else its windings have simply opened which the ohmmeter test would indicate.

John T

Each brand has their own range of sensor Ohm values to move the gauge though it's range.

If you have a service manual for the equipment the gauge was used on, it may give those values.

Also, some gauges are designed for 6-Volts, some for 12-Volts, and so on, and some guages are feed from an IVR... (Instrument Voltage Regulator) that chops the incoming battery voltage at a slow rate, to provide a regulated average voltage to the gauges.

So, yes they can be bench tested, but you need to know the supply voltage and the sensor values.