My car wont start

no job (project) told what are you doing?
I guess this is dead stick question, (LoL no wind or too low RPM question )????????
it is not for a car or truck. is my wild guess,.
but came off a truck 3g ford alternator, is 1992 to 2004 alternator, ???
3G comes new in 30-+ models, up to 225 amps(RPM based always). and 6 or 8 wires,
modle 77xxxx or 82xxxx series best is tell he full part number you we will lie to you. OK
internal regulators and external versions both are made. and matters.
off a 2004 Mustang? 8wire?
yes you can put a switch in he stater wire or the rotor coil spool on external regulated,
but no model ALT told at all or the car it came off of , so no easy snap answers here, lacking such a key fact.
here is the 04mustang, stock OEM wiring of using a 3G 200amp upgrade.
the alternator is dead if pin1 one is open, (simulating key OFF in the car)

the reg is dead and alternator is dead, if pin 1 is cut, same as in the car,
But mY Spidy senses tell me it is no car here are all. or truck.
and I can tell you more secrets here if not used in a car ( untold hyper secrets)
the regulators i all or most alternators self excite themselves.
so if you want the Alternator off line , with no wind or low speed wind say so.
Alternators do go off line at below 500rpm (depends on pulley ratio to engine (alt rpm)
no RPM told at all. (nor load)


https://imgur.com/a/tr6jLxe


https://imgur.com/a/tr6jLxe

Check spark at the spark plug by putting a screw driver up the cover hold it close to an earth and get some one to crank it over ,the spark should jump to earth.

How to voltage drop test starter motor circuit Looking at a wiring diagram an testing the starter circuit with a DMM - digital multi-meter is the way to find the problem . Free wiring diagram's here http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model an engine size. Under system click on engine then under subsystem click on starting . Click the search button then the blue link .
Looking at the diagram you will see this starting circuit is computer controlled . Ignition switch is a low voltage input to the BCM - body control module. A message to the ECM - engine computer from the BCM requesting a start over the serial data network (class2) will energize the relay sending B+ voltage to the S terminal on the starter solenoid . Your best bet mite be to have it towed to a qualified repair shop.

Check fuse. Check wire connection from fusebox. Check wire loom connection. Check the earth from the flasher unit.

If all other plugs fit, just cut the ends off the black wires and put them together.

Your problem could be a few things ..1 Battery flat or low down to 10 volts or lower if when you turn the key the ign lights go out. 2 check earth lead from battery to engine block and from block to body for earth lead(Black lead) 3 Starter motor or RED feed
lead from battery term if all ok then some times wont start ,open the bonnet and turn the key for 5sec and if either term is hot thats the dirty one..

either a bad body ground,or your tranny is locked up,did it run good before you shut it off?

sence you have had bad gas you will need to replace the inine fuel filter this should fix the starting problem but i would beleave you have a O2 sensor that needs to be replaced

u mihgt have a short somewhere,even if u have a bad connection u can have all kinds of problems,do u think u mite have pinched a wire somewhere?double check all connections on battery and starter wires.if u can install a good battery to see if it mite make a differents.let me know what happens GOOD LUCK.

you have a short somewhere in the wiring. it could be a damaged earth and its using the earth for that device, check all earthing points in engine bay usually around were the battery is clean then and see if it happens again