Hello, I have a problem,I keep getting battery low voltage when I sit at a stop light or use the ac. After driving about 1 mile message clears . I have changed the battery and still recieve the message. I was going to change alternater but can not figure out how to remove the s belt wheel tensioner, feels smooth no place to put a socket and scew to back off tensioner. How do you back it off? It's a 2002 s 80 2.9. Thank you

 

I think there might be a plastic cap on the pulley that you need to pry off with a screwdriver to access the bolt. Here's a tutorial for S70, yours is probably similar: http://volvospeed.com/Repair/sbelt70.php

 

Thats how I do it. But also if you look closely with a mirror there is a hole where you would install a torxes socket but it is a big one like a torxes 50 or 55. Thats why I pop the cover off and use a 14 MM wrench.