Starting problem 1999 nissan sentra 4cyl. 5 sp. manual transmission.depress clutch turn key to start engine turns except gauges light up new battery and starter checked out engine not running

Possible issues: too many to list

Do you hear a clicking sound when you turn the key to "START"? If so, I'd say your battery is dead.

Do any of your gauge lights, head lights, radio, etc. work just fine? If so, I'd guess you have a bad ignition, bad coil, or bad starter.

Likely issues:
Dead battery
Bad coil
Bad ignition switch
Bad starter

Since you have power to your accessories, here are a few more things to consider:
1: Automatic transmission not in park or the neutral safety switch is faulty
2: On manual transmissions clutch pedal not depressed or or clutch start switch failure
3: Broken or loose wires in the starting circuit. Inspect all wires and connectors at the battery, starter solenoid, and ignition switch
4: Starter motor pinion jammed in flywheel ring gear. Manual transmission. place transmission in gear and rock the vehicle to manually turn the engine. Remove starter and inspect pinion and flywheel

Connect a voltmeter to the middle pin of the startermotor. Let some start the car, if voltage appears and no start it's likely the starter motor / solenoid.If no voltage appears it might be the clutch / brake switch. If there's a cruise control - these 2 switches are read also when cruising.

are the connections at the terminals (battery & starter ) clean & tight

Try starting it in neutral instead of Park. I suspect neutral safety switch.

By the sound of it. Can you check the Starter Fuse if its still good. you can visually check this by simply taking out the fuse and inspecting if the fillament is still whole. Any breaks in the filament would mean a dead fuse. To find out which fuse to check look at the underside of the fuse box cover and there should be a diagram.

Another potential problem would be the ignition switch. if thats the case there are a lot of ways to go about this but the cheapest way is to simply create a new lead to the starter and add in a push button switch (if done right it would look really cool since most exotic cars are actually started with a push of a button rather than a turn of the key)

most likely a bad cnnection from the battery or at the starter. next time it will not turn over at all have some one tap on the starter with a hammer (or a long bar if you can't get to it with hammer) while you turn the key over.

If the car has a manual transmission you should check the clutch interlock switch. Check connections and fusible links at the + battery terminal as well.

check the switch that the clutch actuates.your ignition sounds like it works.some cars also must be in neutral if yours does the wires for this will plug into the transmission.you can bypass the switch at that point.

is it a manual or automatic?if it's manual check clutch.if it is automatic check transmission fluid.