Headlights come on but it won't start - 1998 Mercury Villager

Someone would need to check for power at the starter coming from the key switch. You could have a faulty neutral safety switch, key switch, or starter.

this could be several problems / need more info

You probably have a ground issue , looking at a wiring diagram or ground distribution diagram to see if these share a commom ground point or share power from same fuse,https://www.youtube.com/watch?v=WoN1nou5t1Q&t=224s circuit with a high resistance problem . Do you know how to test automotive electrical circuits with a DMM - digital multi-meter , how to read an use a wiring diagram to pin point test spots in a circuit . Free wiring diagrams at http://www.bbbind.com/free_tsb.html . Check out these videos on voltage drop testing an basic electrical testing . This is the way to find electrical problems .
Mastering Voltage Drop Testing with Pete Meier and Jerry Truglia YouTube
Electric Testing Techniques You Need to Know

Basic Electricity for Service Techs Ohm law Current Flow Opens Shorts

good luck !

Something must of hit the starter wiring when you drove on your flat tire.

Hello! I don't see a connection between the headlight issue and not starting...However I definitely see a connection with the accident and not starting...When you say "not starting" do you mean the starter doesn't crank the engine or it does crank the engine but won't start? Do you have a meter and a wee bit of experience using one? If you do we can isolate this fault together...Send a comment...Guru...Saailer

Try this procedure:
Check the battery like this:
Turn on the headlights, then try to start the car.
If the headlights do not dim or go out, then the battery is likely ok.
Check that the battery cable plus post, goes to the starter, Minus post to a good ground, like the engine.
If wiring is ok, then look at the starter solenoid for a good connection, and proper voltage at the starter.
Problem is most likely the Solenoid's bendix gear or starting relay, Have someone bang on the starter while you try to start the car. This usually works by dislodging the bendix gear..
Hope this helps.

It had all the symptoms of a low battery. Glad you got it figured out!

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

baterr ywas dead changed it-new battery worked-discharged once air turned on-put in 2nd bateer yseems fimne as long as you don't turn on the air-if you do there is a clicking inside radioconsole and discharges battery

check all the battery leads both ends

won't turn on? you mean start?
do headlights come on?
check brake light won't keep it from starting