When you say it clicks, does it click in the steering column from turning the key, or does it click under the engine from the starter solenoid or starter?
If it is clicking under the engine, then it is either the battery or the starter solenoid or maybe the starter. If it clicks in the steering column, then it might be the switch.
Turn the headlights on. When you try to start it, do the lights dim? If yes, the ignition switch is probably working and it is probably the battery, starter or starter solenoid.
On my 1990, the starter solenoid is mounted to the starter and they are sold together. I think earlier ones might have the starter solenoid on the firewall, like old Fords.