Engine does not turn over when key is turned to "start'!

My 1995 Nissan Truck has 287,000 miles. In the last two months it will periodically fail to turn over when I hit the key. The battery was replaced this past summer and is not the problem. I checked the transmission neutral switch and the clutch switch…both in the start circuit and both ok. I checked the spade connector to the solenoid and it seemed ok, but to make certain that the ignition switch was closing the circuit to the solenoid, I wired into the solenoid wire a test light and turned the key. The light came on, but no energization of the solenoid (no click and clack…good pun, huh?) At this point I removed the starter, took it to Autozone where it checked out ok but I bought a new starter and installed it. It started a few times but the problem wasn’t fixed. I wired in a new wire from where I knew I had juice in the solenoid circuit down to the solenoid with a new spade connector. That worked for one week but now it won’t turn over. What am I missing?

transmission neutral switch and the clutch switch

Usually you have one or the other…not both. Never heard of a MT equipped car not allowing to start it in gear…as long as the clutch is engaged.

Just because turning the key lit up your test light in the solenoid doesn’t mean anything. All it says is that you are getting voltage…doesn’t say anything about current.

Your battery cables may be corroded internally. Check for voltage drops.

Switches may not fail completely. They may just cause voltage drops. A test light is not enough. You have to use a voltmeter. Check the voltage after the electric power has gone through ALL the switches—at the starter solenoid. Disconnect the wire which energizes the starter solenoid. Have someone hold the ignition key to START and check the wire at the starter solenoid. The voltage should be within one volt of the battery voltage (11 1/2 volts), or better.

Disengaged…it won’t start in gear unless the clutch is disengaged.

The neutral switch will allow the starter to engage with the clutch engaged as long as the tranny is in neutral. My trucks were set up like that. I could either hold the clutch pedal in and start it or put it in neutral, let the clutch pedal out, and then start it.

Do you still have a ground wire from engine to body? Sometimes you find one on the bell housing. That is the part of the transmission that connects to the engine. If you ever have a clutch changed, they sometimes forget to put the wire back on. I like mine to go from the back of the engine to the firewall.

The battery was replaced this past summer and is not the problem.

Famous last words. I would suggest checking the batter and the battery cables, including both ends and the ground cable connecting the engine to the frame. Those battery cables can have problems under the insulation and considering their age, I would put them high on my list.

The neutral switch will allow the starter to engage with the clutch engaged as long as the tranny is in neutral. My trucks were set up like that. I could either hold the clutch pedal in and start it or put it in neutral, let the clutch pedal out, and then start it.

I could NEVER do that with ANY of my Nissans. My earlier MT vehicles didn’t have a switch at all.

Yeah, this subject has come up before and it’s apparently not a common setup. Generally just the clutch safety cutout switch is designed in.