Nissan Repair: 95 240SX Auto Not Starting, clutch pedal, starter relay

Question
My wife's 240SX came down with this very strange problem, sometimes the car will start and run fine for a bit and then when you turn it off it won't start back up. When the key is turned to start the ignition, you can hear a click from the dash but the starter does not turn over the motor. The starter was replaced before we purchased the car about 8 months ago. I'm wondering if it's perhaps the starter relay but I can't find it anywhere, I had heard it's behind the dash but I don't know!

I've check the battery terminals, they're clean and tight. Battery is fine, even tested it. When the car decides it want's to start, it does so with no hesitation what-so-ever.

Answer
Zach,

It is probably the starter safety interlock.  If yours is an automatic put your foot on the brake and while turning the key to start the car shift from park to neutral.  If it starts somewhere while the shifter is in motion you know that the safety switch needs to be replaced.  When I say have your foot on the brake it means that if the car starts in gear it will move.  So, make sure your foot is on the brake.  If you have a manual the safety switch is on the clutch pedal and can be bypassed to check it and then, if the car starts, replace the switch.