The back-up lights on my 1988 are black wires. The one from "up front" to the left side circuirt board, and then the one from the left circuit board to the right side. Strange, sinice almost everywhere else black in ground.

Fog lights. With the advent of the 3rd brake light, Volvo, in its infinite wisdom, put in rear fog lights. In 1986 and 1987 the =rear fogs worked only on low beams, in 1988 they changed to fogs on in low or high beams.

Then, sometime after the 1988 model and again in its infinite widsom (or by Euro spec requirements), Volvo eliminated the right side fog light. The idea is that some following driver in the fog will mistake two fog lights for brake lights and therefore make a bad decision.

Your circuit board may be OK for the right side light, but the wire bringing power from the left side and the bulb holder should be missing. Takes the deep holder size. The shallow ones will work, but the larger bulb will be out far enough for the heat to damage the lens.

Gopod Luck,

Bob

:>)