Several times I’ve had trouble starting my car only to get a clicking sound however, my radio does work. I called AAA and the guy tapped on my alternator and my car then started. Any suggestions would be appreciated.
The first thing to do is to clean all of the connections to and from your battery. You can start with the battery terminals themselves, and then follow the battery cables, inspecting and cleaning everyplace those cables go. Do the same from the alternator out the other way. Make sure that one of these paths hits the connections at the starter.
If all of that gets cleaned up and the problem persists you’ll want to have a multimeter and actually check the cables (they can be internally corroded), and have someone test the starter/solenoid.
Has it been a long time since a mechanic has looked under your hood? These battery condition/cable maintiance issues isually get caught at normal service interval times.
If your car had exibited a “no crank” condition due to a battery or cable problem "tapping on the alternator would not fix it. If fact tapping on the alternator will not fix anything.
We do get many posts relating what a AAA person does or says, and many times their diagnosis is suspect. I conclude people think “since my car started after AAA got here they must have done something right”.
Are you sure that he didn’t tap on your starter instead of your alternator?
clicking when trying to start can indicate a failure of the battery (weak batteries will still play radios etc, but can’t provide the high amperage needed to energize the starter and starter solenoid). The starter or the starter solenoid may be defective. Tapping the alternator (if is that what he really did) should do nothing. Clean terminals and connectors, get that battery tested under load (how old is it? How many CCA rating? Many batteries have a useful life of just 4 years or so depending on what you bought. If you can put a jumper on the car and it starts right away, then you have a bad battery.
Do you understand that to clean the battery terminals requires they be disconnected from the battery, and the cable terminals be aggressively cleaned with a wire brush, a file, a knife, or sandpaper? Apply petroleum jelly liberally to the terminals and re-attached to the posts to prevent more corrosion.