Funny how these things come up just when you are having the same issue! Tom's description is spot on(I just had a friend who is a good electrical guy read the 99 schematic for me...his description was identical). My car would start first try sometimes...other times I have turned the key up to 20 times before it engaged the starter. When a no start situation, could never hear anything(solenoid)but the dash lights would dim every time. I swapped the starter...fired right up! Next day...nothing...doh!!! My clutch switch is still in the loop so that is my first thing to by-pass. After that it will be ignition switch!
Ron, the dimming dash lights suggest the switch is working and something downstream is pulling current, which would likely be the solenoid coil. Clean & crimp the spade connector just to be sure it’s not getting some but not enough, then try the jumper from spade to hot. Also Rap on the solenoid. If the jumper rest does nothing then it’s the solenoid.