So what about Question #2—Foglight with 745 unit swapped in, now no Fog light. Forgive me, but I'm pointing out how inconsistancies and changing threads makes remote diagnosis harder than it needs to be.

As I've said, forget the Fog light for now. It's not a legal requirement, and may not even be wired on US cars. And if you have no multimeter or test light (guessing here), I can't tell you where and how to test anything.

I'd guess well over 95% of Directional problems (single light problems) are caused by the bulb itself. its contacts with the bulb holder, or the holder's contacts with the circuit paths on the Light Unit.

If you can snag a meter or test light, test for pulsing voltage on the Blue wire coming in to the Right Light Unit (a flat "spade" plug in terminal), or the center metal strip on the bulb holder, which contacts the center of the bulb's base.

If you get looking at those Right side wires, no Violet means no Fog Light on that side. (Check to see if there is a Violet wire on the right, up top.)

You're ahead of where you were this morning, and tomorrow's another day.

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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

If parking lights are on, on both sides, you can forget about a fuse problem. Stick to the bulbs—make sure the contacts on the holder are clean.
Bend them down a bit for more tension.
Clean the contact surface on the light unit too.
Try twisting the bulb holder back & forth with power on. It may find a position with better contact.

As I think I said elsewhere, the Right Fog may not even be wired (except you had it on earlier). And if it is wired, the Headlights must be on (Low beam, I think) before the Fog Light(s) get power.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.