Rheostat Volume Control Test: GS300
Remove instrument cluster. Remove rheostat volume control. Replace rheostat volume control if it does not operate as follows.
- Connect a jumper wire between positive terminal of a 12-volt battery and terminal No. 2 of rheostat volume control connector. See Fig 1. Ground terminal No. 4. Connect voltmeter between terminals No. 2 and 3. While turning control wheel, voltage should increase and decrease.
- Disconnect all jumper wires. Connect a jumper wire between positive terminal of 12-volt battery and terminal No. 2. Connect another jumper wire between positive terminal of 12- volt battery and terminal No. 5. Ground terminal No. 4. Connect voltmeter between terminals No. 5 and 7. While turning control wheel, voltage should increase and decrease.
- Disconnect all jumper wires. Check for continuity between terminals No. 5 and 6. With control wheel turned fully clockwise, there should be no continuity. With control wheel in any other position, there should be continuity.