My engine cranks slower and slower, then clicks

      The engine cranks  slower and slower, then clicks

If the engine cranks slower and slower until it just clicks, this means the starter motor doesn't have enough power to turn over the engine so it cannot start. This problem should be fairly easy to figure out, as there are just two cables (positive and negative) to deliver the electric current from your battery to the starter motor. A very weak battery is the most common problem in this case

 A bad starter motor also can cause starting problems. In my case it just went completely dead. I had to get towed and waited for a new motor to arrive. Of course, a poor connection or corrosion at the battery terminals or bad battery cables can also cause these symptoms. If the battery is very old, you might want to start with replacing the battery; a new battery is not very expensive.