Tommy laid it out really well. If your relay is in an easy place to get to check the voltage from the switch to that winding. Those relays do have a tendency to burn the contacts in them as they pull a good sized charge when you first operate them. Also I have had relays that the winding went open on. If you want to eliminate the starter quickly and have a heavy lead, just clip 12 volts right onto the input to the starter and see if it turns over. Make sure the car is in neutral if you do this.
Ron
