I've recently purchased the car and now there is an issue with the headlights that started to blink. Also, the lights on the dashboard do not work. Could this be related to battery and the connections, as the gear shift lights went out as well?
If only these three items are acting up, I doubt the battery is to blame. Also, the headlamps share separate ground connections, so a poor ground is not the issue. The Central Electronic module (CEM) acts as a gateway between the high and low speed data networks in your vehicle. It also affects many different parts of the vehicle, so the CEM may be one place to look.
The instrument cluster module (DIM) could also be to blame, as it may be sharing bogus information over the network. Your Volvo involves dozens of different control modules communicating on a data bus, which can be difficult to diagnose. I suggest you leave this one to the professionals, such as the team at YourMechanic. They will be able to inspect your headlight system and let you know what exactly needs repair.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing