Vehicle Not Starting

When this happens, do the head lights and dome lights work? Does the dash light up or is everything totally dead?

Caradiodoc

A good suspect is the clutch switch. The next time it doesn't crank, leave the transmission out of gear and head to the starter relay under the hood. There are two ways to bypass it. One is to pop the plastic cover off, reinstall the relay, and squeeze the contact. If the starter cranks the engine, that proves the starter and battery cables are ok. You can also use a piece of wire to bypass the relay. A stretched out paper clip works great. Remove the starter relay and look at the five pins. Two are on the sides and are parallel to each other. Disregard those and the middle pin between them. That leaves two pins that form the letter "T". If numbers are molded into the plastic or printed on the cover, they will be terminals 30 and 87. Jump those two terminals in the socket and the engine should crank.

If that works, there is a problem in the low-current circuit coming from the ignition switch to activate that relay. The clutch switch is in that circuit.

Caradiodoc

Disconnecting it WILL make it not crank. That is the same thing as not pushing the pedal. You would have to jumper the wires in the harness connector with a stretched out paper clip to mimic pushing the pedal.

If that still doesn't work, fetch a test light. We can break this down into four circuits, and figure out which one has the problem by taking four measurements in the starter relay socket.

Caradiodoc