Hey all.

I have a 2007 XC70 T5, and I'm experiencing some strange issues. The RPMs "hunt" at idle some of the time. When this is occurring, I also get an error about lightbulbs being out. The errors cycle rhythmically with the idle variations, which makes me think they're related, though I can't wrap my head around how or why. Could just be coincidence.

The car has had issues with the vacuum systems (replaced a coupling six months ago, followed shortly by replacing the MAF sensor) but I haven't gotten a check engine light since that last service about six months ago.

My left low-beam headlight isn't working; dealership attempted replacing bulb, still not working.

I'm about ready to take it into the shop about these issues, but something makes me think there's something wrong with the electrical system. Figured I'd see if these symptoms looked familiar to anyone before I take her in. Here's a video of the issue if anyone's interested

Video

 

Did you get this fixed? If so what was it?
It sounds like a bad ground or loose connection somewhere.

 

It could be electrical being loosen some where, that could lead to bulbs failure, head light not work and RPM "hunt"

 

Again, how old is the battery? 4 to 5 years max. That would be the first step if your battery is older than that. And yes I know your battery still starts the car,....irrespective of that if it's older than 4 years in a southern climate or 5 up north it needs to go. Good luck.