thanks for all the responses! job is complete!

Easy. Your Volvo 240 owner manual or a Bentley, Haynes, or Volvo green OEM factory shop service manual helps.

The clear lens can separate from the reflector body on the big, square 1986 and later 240 headlights.

At the front center bottom edge of the clear head light lens, gently pull forward and up. You may need to remove the grille to see the clear headlight lens pulling away from the reflector body.

Separation of the the reflector body from the clear head light lens can allow moisture and biomatter intrusion into the head light reflector chamber.

You can search the brickboard for threads containing various procedures and materials to clean and re-seal the headlight lens and the reflector body for 1986 big square headlight 240s.

You usually want to replace head light in pairs or at least use the same make and model bulb.

It can hurt to check the wiring, verify headlight and turn signal wire harness an grounds, and the like.

cheers,

Egged and Nawgggged (as in eggnog).
--
Eggnog.

It is easy to change just the bulb as long as you can get your hand in behind the headlight. The black ring turns to the left (looking from the backside) to loosen the holder from the shell of the headlight. It is then pulled because it is only held by a reddish/orange o-ring.

You might want to notice how the wire connects to the holder and note the orientation of the flat side to other things around it. This will help you to realign it to the three unevenly spaced notches in the hole later. The holder only goes in one way and so does the bulb into the holder.

Just do your best not to touch the glass of the bulb when handling and inserting it. If you do wipe off any finger oils using alcohol and its best to use the non-drinking type. (:)

Putting it back is just a reverse operation.

Phil

You have a 1991, which has a simple small bulb, as opposed to say an '86, which has two giant bulb units on each side of the grill to deal with. Your change out is easy.

Open the hood and go behind the light bulb unit in question. You will find the small bulb sticking out of the light unit, like the cone of an eye with something sticking out behind it. You will also see a wire attached to this bulb/conical back-end setup. Grab this small bulb/wire set-up and turn the plastic locking nut at the base counterclockwise. After only about an inch of turning counterclockside, you will notice that this large plastic nut will loose its tension. Once it's loose, gently pull it out on this bulb setup from the overall conical light unit, BUT, make sure you make a mental notation as to which end of this large plastic nut is front and back. You may even want to practice putting the dead unit right back into the light unit such as to make it easier with the Real McCoy.

Next, after you have pulled out the lone bulb, you will notice that the bulb itself is attached to this wire, with some sort of clip holding the two parts together. This clip is one of those "clip on/snap on" type devices whereby the new bulb gets locked into this dangling piece of wiring. Maybe there are better ways to do it, but I just took a thin screwdriver and gently prided up this snap on clip as I simultaneously pulled out the dead bulb from this wiring mechanism/harness. From there, push/clip in a new bulb. The new bulb will have indentations/clips to make it line up with this clipping/snapping part of his wiring harness, so make sure it is lined up.

Finally, push this whole new bulb/wiring harness flush with that overall conical bulb section. If you do not line and push it in flush, you'll be out there forever cursing yourself, as the plastic nut will just keep turning and turning without grabbing anything. I recently did this and I did not push the new bulb in flush enough, thereby making a mountain out of molehill. When in doubt, or stuck, try gently playing/twisting with the other working light, being careful not to fully take it out of its own socket, such as to get the hang of it.

Let's just call these directions "light bulb changing for the light bulb impaired". I spent ten minutes changing the bulb the other night on a 1990 245 when it should have taken two minutes; I didn't push the bulb in flush enough so the plastic nut wouldn't catch and thus I was fiddling and diddling for ten minutes.

Keep your hands off the bulb itself as well as that supposedly shortens the lifespan of the bulb, should your potentially oily fingers get on it or something....

If it is just the bulb then it's a piece of cake. Just twist off the round black bulb holder and take out the bulb. Plug in a new one and twist the bulb holder knob thing tight. If you are replaceing the entire assembly then you have more work to do. Expect to cut the nuts off of the 4 bolts as they may be rusty and the bolts will spin in the headlight housing.