i went to quote a job on a 94 850 last night and noticed it didnt have either reverse lights when the owner was moving the car. i checked the bulbs and they were fine. fuse was good (#27 i think). wheres the switch located? is this associated with any other problems that people have seen? also the bulbs under the back up light wasnt on, not sure what that one is. it has tails, signals and brakes, maybe another tail?

anything helps

 

I believe there is a switch at the shifter. The PNP controls them as well. Stand behind the car while someone slowly shifts from P to N to see if they ever come on.

The ignition switch is likely the most common failure. Have someone move the key back and forth a little while it's in reverse.

 

Here is a write up on a PNP R&R with pictures.

http://www.matthewsvolvosite.com/for...hp?f=1&t=29930

There is a difference between the sedan and wagon tail light lay out. Which one is it you are working on?
If the owner has the manual it will tell you the layout on the back. Well, at least mine has the diagram of which is which and bulb number on the back cover of the owners manual.

 

The bulbs under the backup light are the rear fog lights on the wagon and the sedan.