Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1997 Lexus SC 400FACTORY OEM SERVICE PROCEDURE
Rheostat Light Control
NOTE:
Rheostat and rheostat light control are separate components. Rheostat is an electronic module that receives signals from rheostat light control (control wheel).
Remove instrument cluster. Replace rheostat light control if it does not test as follows.
- Resistance between terminals No. 3 and 4 of rheostat light control connector should be about 10,000 ohms. See Fig 1.
- While rotating control wheel in "B" direction, resistance between terminals No. 1 and 3 should vary from about 10,000 ohms to zero ohms.
- With control wheel in "A" position, there should be no continuity between terminals No. 1 and 3.
- With control wheel in position that turns lights off, there should be no continuity between terminals No. 7 and 8.
- With control wheel in position that turns lights on, there should be continuity between terminals No. 7 and 8.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.