The Consumer Information website from the Federal Trade Commissions offers information on troubleshooting, repairing and preventing automotive problems. Common troubleshooting areas include the alternator, battery, starter, muffler and tune-up, according to the FTC.
Loose wiring can make an alternator appear faulty, and loose battery terminals can make the battery seem dead or defective. What appears to be a defective starter actually may be a dead battery or poor connection, and a loud rumbling noise under the vehicle indicates a need for a new muffler or exhaust pipe.
Another trustworthy source is the National Institute for Automotive Service Excellence. The ASE is an independent non-profit organization working to improve the quality of vehicle repair and service by testing and certifying automotive professionals.