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. The entire cluster may need replacement if incorporated into the printed circuit board.

IVRs or instrument voltage regulators perform the same function as a voltage limiter, with a different name. They consist of a bimetallic strip with 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.