Osram and Phillips are / were OEM bulbs. Not that it matters now.

Yep, you're utterly correct in your comprehensive research of the bulb failure sensor and terminology. Inside are Reed relays that, when encountering current draw imbalance (unbalanced electromagnets), that close the circuit to light the bulb failure dash indicator.

You can replace the lenses. It helps to clean what reflective material remains in the reflector chamber. There exists reflective paint, or some will use silver color paint of different types, to restore lighting brightness, by painting the reflective surface of the bulb chamber.

The from park / turn signal light lenses do lose transparency with ambient condition exposure in over 2.5 decades.

These lenses are secure using three stainless screws. Under the screw head is a compliant nylon washer to form a seal to prevent 'weather' getting in. These nylon washers tend to break or distort and become lost.

Also, the lens lip presses against a rubber a foam or o-ring like seal in the groove recess. The seal has a small gap in the bottom to allow drainage. If in poor condition, you can replace this seal from Volvo or find a replacement material suitable for the application. (I'd not replaced these or used junkyard parts.)

When installing your replacement lenses, unless you replace the entire front corner / park / turn signal light assemblies with new ...

... do not merely insert the screw and tighten. There will be a thread already cut by that screw insertion at the factory.

Insert the screw, and turn counter slowly clockwise with gentle force, so the screw thread aligns and sets with the thread in the recess, and then turn clockwise to tighten.

Else, merely turning the screw clockwise cuts a new thread, and can increase the chance of stripping the thread in the recess.

Also, Old Duke, deviating slightly from your thread topic, have you replaced the headlamp assemblies or service them?

I ask as the factory adhesive, even for a garage queen of some 25-26 years, fails on all 240s with the 1986+ large plastic lens.

Place your finger just under the bottom center lip of the head light lens and lift up?

Does it lift up, pivoting under the top chrome piece, away from the head light reflector body.

If yes, you can clean and glue them back together if the reflector remains good, or replace the assemblies with new. The e-code glass versions are better. Though other reports quality results with some aftermarket replacement 240 lenses. (I can find that thread.)

I can post the procedure for you in a new thread if you encounter the '240 1986+ US DOT plastic lens separating from the headlamp reflector body (housing) syndrome' and you wish to clean and glue them back together.

Questions?

Hope that halps yoooo. Best wishes for more fresh seafood!

MacDuffed.
(Frozen shrimps, mushrooms, diced onion, canned salmon, canned clams, tomato paste for a poor person's hollow day cioppino.)
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