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.
1999 Audi A6 BaseFACTORY OEM SERVICE PROCEDURE
Diode Assembly
- Set ohmmeter on 100x scale. Connect ohmmeter leads between generator output terminal and each 3 stator terminals, in turn. See Fig 1 . Reverse ohmmeter leads. If ohmmeter indicates continuity in only one direction, go to next step. If ohmmeter indicates continuity in both directions, replace diode assembly.
- Connect ohmmeter leads between negative plate and each 3 stator terminals, in turn. Reverse ohmmeter leads. If ohmmeter indicates continuity in only one direction, go to next step. If ohmmeter indicates continuity in both directions, replace diode assembly.
- Connect ohmmeter leads between Blue (D+) wire terminal and each 3 stator terminals, in turn. Reverse ohmmeter leads. If ohmmeter indicates continuity in only one direction, diode assembly is okay. If ohmmeter indicates continuity in both directions, replace diode assembly.
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.