I need to know which wires to test for the css switch. I know its going bad because I can't start it with the clutch engaged when its hot outside. I live in AZ AKA Hell. I was told by the dealer mechanic who works on the car that its most likely the switch, but I want to test it to be sure.

 

The starter interlock clutch pedal switch is located on the firewall side high up behind the clutch pedal. It has a connector on it, and switch position is also adjustable.
There are only two wires involved.
Disconnect your battery negative, unplug the switch connector, give both sides a good shot of contact cleaner. Squirt contact cleaner into the switch via the plunger, and work it back and forth to clean and loosen things up.
With a continuity meter, measure the continuity on the switch side contacts of the 2 pin connector. You should see an open circuit with the switch plunger extended, and a short circuit with the plunger depressed.
If the switch is OK (and my guess is that it is) , you have a tolerance buildup problem due to normal linkage wear, so your choice is to go through a full clutch pedal/ linkage setup procedure, or take the lazy way out and just loosen up the clutch switch mounting screws and move it toward the pedal a bit, then retighten it. Don't overdo it though or you'll break the switch when you depress the clutch to its limit.
Reconnect the battery negative, test your starting, if OK, reprogram your radio and clock.