Instrument Cluster Voltage Limiter
If all of the gauges in an instrument cluster are displaying maximum output, it is likely the voltage limiter is faulty. This part reduces and controls voltage to the instrument gauges in the instrument panel. Many of these regulators are located directly on the back of the cluster. In many late model vehicles they have been incorporated into a printed circuit board and the entire cluster may need to be replaced if the voltage limiter is faulty.
IVR's or instrument voltage regulators perform the same function as a voltage limiter, just with a different name. They consist of a bimetallic strip, two contact points, with one arm wrapped with a grounded heating coil. This regulates the voltage at or near 5 volts. They are often located on the back of the instrument panel. The instrument cluster will likely have to be removed to replace an IVR. Check with the manufacturer’s manual for location and testing specifications.
Note that there is approximately 5 volts sent to the gauges. These regulators should reduce the voltage from 12 volts to 5 volts. This is regardless of the charging system’s voltage. When the voltage limiter/regulator is faulty, the gauges will read higher than the actual condition.