Re: Spyder fog light relay?
I'd guess the relay for the fogs (assuming it has a relay, might just be off the switch for just one 21w bulb?) would be in the cluster of fuses/relays under the dash to the right of the steering column?
If the reverse light isn't coming on either then I'd suspect the sub-loom going to the rear clam. My brake lights did something similar last year. There was definitely 12v at the last connector before it went into the conduit through the tunnel but there was 0v at the first connector at the other end. I don't know if there are any connectors within the conduit (hope not!) but the only explanation was that there was a broken wire or loose connector in the conduit. I ran a new wire along the outside and joined it in either end and that fixed the problem.
Worth checking the earth wire too - just use the resistance setting or continuity beeper between the wire near the lamps and a good earth e.g. the engine frame.
The rev counter works off the ecu signal so check all the connectors on the big multi plug and the engine loom to body loom connector.
I also found there was a lump of wires with bullets under the dash, left hand side, where some of the outer insulators on the bullets had pulled back and they were shorting against each other giving weird results...
Good luck!