Volvo Troubleshooting Questions? Ask a Mechanic for Answers ASAP
The alternator on 2005+ vehicles uses a different regulator that the previous years. This should use an ACM (Alternator Control Module) style regulator which communicates with the CEM through the LIN-network. If the alternator has been replaced, ensure the correct one was installed. An incorrect alternator will send 12 V on the Green/White wire. Normally, that wire will have square waves on it.
If an alternator was replaced with an incorrect,you could swap the regulator from the original to the new one without any problems.
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