When I turn the key to start, nothing happens. No click, buzz, or anything. If I jump the start solenoid, it turns over just fine. Wipers and lights (most of them) are working also, so it seems the switch itself is functioning.
That depends on the year. There was no such thing as a clutch safety switch till stupid people started driving and blaming others for their stupidity.If it's a 4-speed with clutch safety switch maybe the connector wire unplugged or switch is bad. The switch grounds the starter relay when the clutch pedal is depressed.
Or a test light.No, on mine it was just the wire coming from the firewall to the starter relay and I just spliced a new wire in. I used a voltmeter and traced it down that way. If you turn the key to the on position and take a screwdriver and jump the posts on the relay and it starts, it's likely a short, the switch or the relay. Unless...you still haven't said what year car, 4 speed or auto. If you do have neutral safety switch, that could also be the culprit.
You really need a voltmeter to track it down