Yup indeedy, if 83 is same as 91 then the fuse box is under the kick panel of the passenger side, you might have a bit of board clipped in to hide it.

The rear fog will be fused but it might not have a fuse of it's own, so it might be in with say the reg plate lights or the dash lights if you know what I mean. What's the problem ? If the fog isn't working then check if anything else isn't, lights, indicators etc could be lumped in with the fuse of one of those. If you need anymore information then let me know and I'll see what I can find out for you.
