Well, I did a web search for the relay, didn't find any pinouts anywhere.
Got an ohm meter? Use the ohm meter to determine the coil terminals (i.e. look for resistance between two terminals).
Don't have an ohm meter? Ok, use a pair of jumper wires from a 12 volt source (car battery would be fine). Touch the wires to pairs of terminals until you hear a click when the relay pulls in.
Once you've found the coil terminals you're home free!
There are a couple of ways of wiring up the relay, depending primarily if you want to switch hot (+12 volts) or switch ground.
Switching ground: Heavy wire from +12 volts (battery positive) to one coil terminal and one contact terminal. Remaining coil terminal goes to the dash switch with a light gauge wire (the switch then is connected to ground). Remaining contact terminal on the relay goes to the hor or fan with a heavy wire. Other end of the fan or horn goes to ground.
Clear as mud?
