Headlights wont turn on

Sounds like the battery is weak. Yea 12 volts its good, but it needs it under the load also. Your local auto parts store Sb able to test it

Possibly a battery cable terminal or the connection at the starter.
Sometimes a loose or faulty wire can barely work until a load is put on it then it just shuts down. Test power flow at starter before and after turning the key. Replace battery cable ends and if the problem persists, replace entire cable.

You have the solenoid exciter wire touch the bat terminal on the starter. You need to loosen the cable stud and turn and make sure it is not hitting the smaller terminal. the small wire should be going to the S post or terminal

you mean it wont crank, it must crank to start.
1: bad starter system
2: weak battery even a new battery can be weak.
if you dont charge it first.
or if it starts ok then wont later, that means cars charge system failure.

can you jump start engine? with jumper cables.
that be a big clue there, proving starter works but battery was weak.
if the battery is fully charged.
you can hot wire the starter solenoid, (tiny terminal)
if car cranks now, the key start wire is failing.
A/T or M/T tranny? both use different path here....??????

if you cant hot wire it, then that means the stater is bad
the cables bad or the battery is not really connected.
or possible the engine is seized, can you hand turn over the engine at the front crank bolt (CW , facing rear, in neutral)
if not motor is seized.
some times even the starter and rig gear can be seized.
the starter can be bench tested. too.
http://www.fixkick.com/nocrank.html

BATTERY TERMINALS GET CORROSION AND LOSE THEIR CONNECTION AND UNLESS YOU HAVE A HEAVY SET OF JUMPERS YOU WONT GET ENOUGH POWER TO START ENGINE ,TRY REMOVING BATTERY TERMINALS AND SCRAPING THEM CLEAN, IF VEHICLE THEN STARTS COVER BATTERY TERMINALS WITH GREASE TO HELP PREVENT THIS FROM HAPPENING AGAIN

1st check battery terminals to be making connections,next,make sure battery fully charged,then move to fuse box under the hood for burnt battery fuse, then check battery charge,if good,then suspect bad connection to starter (wires) then suspect bad starter. if not that,then try to turn engine over manually by crankshaft bolt to see if cranks locked. thank you for choosing fixya.com

This job is easy to do, dissconnect battery terminal wait 3 min, before continuing, next remove cooler line clamp off starter, then remove the cable wire and the small wire from the starter, next remove the two bolts holding the starter and starter is removed,
the location is at rear of the engine, if you look at where the engine and trany meet the starter should be it thatr area at the top,

Could be the cables or the starter. Remove the starter and have it tested.

The problem is either the starter solinoid (located on fender near battery) or you are not getting power to the "s" terminal on the starter solinoid from the ignition switch. If you follow the positive battery cable from the battery you'll follow it to the solinoid. Remove the small wire from the terminal marked "s" on the solinoid and using a screwdriver jump from "s" terminal (not the wire) to where positive battery cable connects to solinoid. (with battery connected). If starter doesn't do anything the solinoid is bad. If starter cranks then you are not getting voltage from ignition switch through "s" terminal wire.

Did you use the same gauge wire? May be the wire gauge is not heavy enough to carry the current to turn engine over. Does starter make a clicking noise. Check battery voltage.