I bought a kit from ebay with hella d fog lights and brackets made for the 4runner. The kit came with a switch that you needed to wire from the plug where the light stalk plugs in on the side of the steering column. But what I did was to buy a stalk with the fog light controls and plug and play, no need to play with the wiring.
There are several 'empty' pig tails behind the dash about where the coveted RR Diff Lock button would be. In your '01 it's in the section above your left knee while driving. What it will be is a plastic plug. At the moment I can't remember what the plug looks like. The factory switch, non stalk mounted, has 4 prongs (IIRC).