CGT no start

[Craig D. Niederst]

My brother's '86 CGT is pulling the no start routine. Unlike in previous episodes (bad fuel pump relay, fouled spark plugs, etc), the car does not crank at all. All lights work fine, and the voltage gauge in the center console reads ~12V. Starter does not click or do anything at all when the key is turned. Archives basically say its either the starter, solenoid, ignition switch or starter relay. I had driven the car earlier today, and everything was fine (brother also says nothing out of the ordinary in starting the car of late either). Is the best way to diagnose this problem to run 12V from the battery to the solenoid and attempt to "jump start" the car? Car is not at home, and need a quick way to diagnose this problem. TIA.

Craig
'92 100S (97k)
'86 CGT (207k)