Technical Horn Relay Connections

Just got this 6v Horn Relay from Napa and as luck would have it, there are no letters telling me which is the Switch, Battery, and Horn terminals-only numbers. From the picture, I "think" 3 = Switch...5 = Battery, and 1 = Horn. I would really appreciate it if someone can confirm or correct me. Steve.

 

3- battery +
5- horn wire (which goes to ground via the horn ****on)
1- horn

 

Many thanks!