Had a problem with my wife's car yesterday - even with a freshly-charged battery, it wouldn't start. The headlights and dash lights were bright, but absolutely nothing happened when you turned the key.

Since I didn't even hear the starter solenoid clicking, I figured the problem was electrical rather than mechanical, and for once, the first thing I checked was actually the problem. The clutch position sensor had popped off of the clutch master cylinder housing down by the pedals. So when she tried to start the car, it refused, thinking she didn't have the clutch depressed.

It's a strange-looking switch - really just a strip of black plastic with three wires coming out of it, so I think it must be some kind of magnetic proximity switch. I snapped it back into place and the car started right up.

Sometimes it's something simple, and for that, I'm grateful.