I installed a new head unit in my '04 V70R yesterday and everything worked fine except I was getting engine whine through the speakers. Pulled it back out today to make some adjustments after researching issues with the factory amp adapter cable. I hooked the battery back up to test it out and noticed I had an SRS Service Urgent warning on the dash that wasn't there before. The only thing that was different from yesterday is I forgot to plug the AC unit back in before hooking the battery back up. Could that have tripped the warning or is there something else in that area that I could have hit? I didn't unplug anything else.