Checking the voltage regulator

The voltage stabilizer equalizes the operating voltage for indicating instruments. The voltage stabilizer must be checked when the fuel gauge and coolant temperature gauges give incorrect readings.

Remove the bezel and protective glass of the instrument panel. Do not disconnect the battery earth cable.

Remove the device on the left.

Turn on the ignition.

Up to 7/90:

Connect voltmeter to positive input -1- and ground -2-. The prescribed voltage value is approximately the same as the battery voltage (12 volt). If the voltmeter shows a different value, using the electrical circuit, find an open wire.

Switch off the ignition.

Install the device on the left.

Remove speedometer.



Check the output voltage by connecting a voltmeter between the positive output -3- and ground -2-. The prescribed voltage value is 9.5-10.5 volts. Otherwise, there is a break on the printed circuit board or a defective voltage regulator, and the defective assembly must be replaced.

Since 8/90:

Check the supply voltage by connecting a voltmeter between terminals 15 -a- and ground -b-. The prescribed value is approximately the voltage of the battery (12 V). If the voltmeter shows a different value, use the electrical circuit to find a broken wire.

Check the output voltage by connecting a voltmeter between output -c- and ground -b-. The prescribed voltage value is 9.5-10.5 volts. Otherwise, the voltage regulator is defective and must be replaced.