Q: The truck wasn't starting up or making any noise. I replaced the starter and it still doesn't want to start up. It just makes a clicking noise

Hey there. You have a bad battery or there is a bad connection in the starting system. The battery should be load tested and the state of charge should be checked with a hydrometer. Your starter requires about ten times more power from the battery than any other system in your car. Even if the headlights and all other electrical components work, it is not a good indicator of the condition of the battery. So a thorough testing of the battery should be performed first.

If the battery checks out, then the problem is a bad connection in the starting circuit. The first test I do, which may be irrelevant since you have already replaced the starter, is to tap on the starter with a hammer while someone is attempting to start it. If it cranks the motor, it needs a starter. It is possible a new starter is bad, so there is still some value in performing this test.

If this doesn’t reveal a bad starter, another simple and test is to attempt to crank the car for up to thirty seconds. Pay attention to smoke or any electrical burning smells that might occur. If you experience one of these, immediately stop and look under the hood for a hot spot in the battery cable connections. Feel both battery posts, the positive and negative battery cables, the ground connection at the frame and the main power connection at the starter. If any of these are hot or warm, it is a bad connection.

If that doesn’t reveal anything, the next step is to use a test light to see if the starter solenoid is getting power from the ignition switch. If it is not, you will need to use a test light to find our where the connection is lost. The suspect parts are the ignition switch and the neutral safety switch (aka the transmission range switch). You will need access to a wiring diagram and a test light for this portion of the testing.

If you should require further assistance, I recommend having a professional technician, like one from YourMechanic, diagnose your starting issue so that this can be repaired.