Which system does Toyota use on the '93? Or to ask this another way, which pole on the relay do you wire to the battery?

Nobody has an answer for this? I'm pretty sure it's switched ground, but would be nice to know for sure.

The answer, according a former Toyota engineer is that it depends, but generally switched ground for most of the system. Horn is an exception, but lights and computer are switched ground instead of switched hot.

Horns and rough wiring:







The buss bar, fuse holder and a relay holder will all be mounted on a piece of phenolic, which will be mounted on lengths of threaded rod to hold it above the fender and the factory wire runs, but low enough to be below the level of the main fuse box. Relay holder will have relays for horns, headlights, front fog lights. Rear fog lights only draw as much as brake lights so need for a relay.