Harold, the same relays can be used for both. The relays take just a little current from the headlight switch (or horn button in this case) and can handle upwards of 30 amps (exact rating will be on the packaging) to whatever your controlling {lights or horn). In fact when I work on modern vehicles and am trouble shooting, I've found that the relays on my cars are all the same I. E. I can swap one for the others to check for a bad relay. Most cars have four or so relays mounted under the hood near the fuses etc.
David
