Hello fellow Volvo enthusiasts. We drive a 2010 xc70 and a 2005 v8 xc90. I recently purchased the xc90 to pull a pop-up camper. My local Volvo repair shop declined to install the trailer wiring. I had the RV dealer where I purchased the pop-up install the trailer wiring, and it worked just fine for the first 2 uses, which were short trips locally. As I hooked up last week-end, the "Over charging, stop vehicle" appeared on the dashboard menu. I understand that the power windows etc. are designed to stop working. After taking the xc90 to my Volvo repair shop, (no dealers in my area), I was told the alternator had failed due to the trailer wiring using universal module. Factory alternator was installed and the fault code went away. I'm being told to install correct factory trailer wiring or loose my new alternator warrantee. My repair shop has quoted a cost of $671,00 to install new wiring. I,m a bit confused after reading other member experience with trailer wiring. Any help to avoid another $1200,00 alternator or void my warrantee would be appreciated. Thanks a lot gjones