Having a Ford that won't start can be frustrating. The starting system has so many components, that just testing everything out seems daunting and complicated, but if you go through the starting process systematically, then it can be done easily, and you can move on to fixing the problem. In this case, the project truck is a Ford truck, but the process is similar for other Ford vehicles as well.
Pop the hood and locate the battery in the engine compartment. Visually follow the leads from the positive terminal until one of them leads you to the starter solenoid. This is a small relay pack with a battery lead running into one side, then another battery lead coming out from the other.
Clip the black clip from the 12-volt test light onto the engine block or a nearby bracket, then place the pointed end of the test light on the solenoid, on the battery lead opposite the one that goes to the battery. This is the cable that goes to the starter, and this will help to determine if the problem is the solenoid or the starter itself.
Have your assistant attempt to start the truck while you have the test light on the lead. If the light on the test light illuminates, then the solenoid is working correctly. If it doesn't, then the problem is most likely with the solenoid. If it does illuminate, then the starter may need to be replaced.
Set the multimeter using the knob on the face to the DC voltage setting, and plug in the red and black leads into the multimeter. Hold the black lead from the multimeter on the engine block, and then place the red lead onto the battery terminal on the back of the alternator. Have your assistant start the vehicle. If it starts, look at the multimeter to determine what the voltage is. It should read between 12 and 15 volts. If it doesn't, then the alternator isn't charging the battery enough, which could cause the intermittent starting issues. The alternator may need to be replaced. If it is charging correctly, proceed to the next step.
Move the red lead on the multimeter onto the positive terminal on the battery and move the black lead onto the negative terminal on the battery. It should read between 11-13 volts, and if it doesn't, replace the battery. This should fix the problem.
