Instrument Panel Voltage Limiter
The voltage limiter reduces and controls the voltage to the instrument gauges in the instrument panel. Many of these regulators are located directly on the back of the cluster. If it's been incorporated into the printed circuit board, the entire cluster may need replacement.
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. Check with the manufacturer's manual for location and testing specifications.
Note that there are approximately 5 volts sent to the gauges. These regulators reduce the voltage from 12 to 5 volts regardless of the charging system's voltage. When the voltage limiter/regulator is faulty, the gauges read higher than the actual condition. If all of the gauges in an instrument cluster are displaying maximum output, suspect the voltage limiter is faulty.