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.
12 42 500 Replacing Battery Positive Lead (Between Starter, Alternator And Battery Positive Terminal)
Necessary preliminary tasks:
- Read out fault memory of DME control unit
- Switch off ignition
- Disconnect battery negative lead. See 61 20 900 DISCONNECTING AND CONNECTING BATTERY NEGATIVE LEAD (CONVERTIBLE)
or 61 20 900 DISCONNECTING AND CONNECTING BATTERY NEGATIVE LEAD (COUPE)
.
Follow instructions for disconnecting and connecting battery . See 12 00... Instructions For Disconnecting And Connecting Battery .
- Remove intake air manifold . See 11 61 050 REMOVING AND INSTALLING AIR INTAKE MANIFOLD (N52K) .
Remove protective cap (not shown).
Release nut, remove battery positive lead (1) from battery positive terminal.
Tightening torque, see 12 42 1AZ in STARTER LEAD .
Release nut and remove battery positive lead (1) from alternator.
Tightening torque, see 12 31 1AZ in ALTERNATOR WITH DRIVE AND MOUNT .
Unlock plug (1) and remove.
Unfasten nut.
Tightening torque, see 12 41 3AZ in 12 41 STARTER MOTOR WITH MOUNTING .
Detach battery positive lead (2) from starter motor and remove.
NO RELATED
Use the Manual With the Right Hardware
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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.