Dick-
Sounds like you're getting power to the relay, but not to the starter itself, or the starter is seized.
Start first with Chuck's suggestions above.
Then I'd next y connect a voltmeter negative lead to the ground and use the other (positive) lead to
1. See if the large cable bringing power into the starter solenoid is live with the full battery voltage, then
2. connect it to the output side of the relay and see if when the starter is activated and the klicking starts, the full voltage is being delivered to the cable or directly to the starter if that's how it's designed (solenoid on starter body, wired internally).
I'd also find out if I could spin the starter motor manually with a tool to see if the armature is seized.
If the motor is seized, you need a new one or a rebuild by a competent electrical technician.
If the motor is not seized, then maybe the solenoid is bad, especially if you can determine in #2 above that the full voltage is not being applied to the motor when the key is turned.
If you can't make a determination, the motor and solenoid can be detached and taken to a competent person or shop.
You could also "jump" the starter solenoid by supplying power directly to the motor from the supply (inlet) side of the solenoid and/or battery with a heavy cable (00 or better) to see if the motor itself spins and is is good, which would also help you find out where the open circuit occurs. I don't think this would back up voltage and current into anywhere it would do any damage, but I'm not familiar with your particular motor.
Be care when doing all of this, the size of the current involved can produce a lot of heat and start a fire, and the motor and it's Bendix drive gears can remove fingers easily.
Sometimes difficult repairs are best left to a professional repairman.
Always use caution, and when in grave doubt, don't!
Joe. :teeth :thup