Other than the obvious answer, Read the manual... you could simply follow the Battery's positive "+" wire to it. The batter connects to the starter on the positive side and to frame ground on the negative.
The starter or battery cables/terminals are corrode.
follow the thick positive wire from the battery and you will find a stater at the end of that rainbow
Very easy. Purchase the new starter and you see how easy it is.
Make sure the relay is supplying the 12 volts to the starter - if so remove the starter and go get a rebuilt on to replace it or learn how to repair it yourself.
Usually against the inner fender wall maybe behind the battery
starter is out, motor is locked up or your starter solenoid is out.
Location of starter on 89 ford f150
On the Starter
How do I locate the heater blend door actuator in a Ford f150 pickup
where is the starter locate on 1997 grand am
on bottom side of engine
The 2000 Ford F150 does not have a co2 sensor to my knowledge. They do have several O2 sensors and they are all threaded into the exhaust system in various places depending on engine size.