I am planning on installing fog lights on my 1991 K75S. A previous owner apparently had auxiliary lighting and removed it: There is a pair of red/black wires in the fairing under the headlight that are connected to the OEM auxiliary light switch. I'm trying to figure out if I should use that wiring, or tear it out and wire it myself. I'm leaning very heavily toward re-wiring it myself, but I wanted to see if I'm missing something through my lack of experience with automotive relays.
The good: The switch controls the voltage on the red wire--it is 12V when the switch is on. The black wire is grounded. The PO used a relay, so the current is not flowing through the switch.
The bad: I've traced out the relay wiring, shown the diagram below. The relay is wired completely backwards from every diagram that I've seen: pin 85 goes to +12V instead of ground, while 86 goes to ground through the switch. Pin 30 goes to the light instead of coming from the battery, while 87 is connected to the battery's positive terminal. The fuse is between the relay and the light rather than between the relay and the battery positive connection.
The ugly: The PO was very fond of red wires, although he occasionally connected red wires to black wires, picture attached. The combinations occasionally are connected to ground, and sometimes to +12V. My favorite is a red/black connection made with a female spade connector (turns out that's ground).
So is this some totally backwards wiring that just happens to work by accident, or is this an uncommon but still acceptable arrangement of wiring up the relay?
A minor note but perhaps pertinent: Because the circuit uses the unswitched 12V from the connector for special equipment, the lights will come on without the key being turned on. I'm going to change that so that the fog lights can only be used when the low beams are on due to some rules of the state of Virginia.