I remember years ago a customer of mine called because she was stranded at McDonalds. Her car wouldn’t start, it wouldn’t even crank over. Luckily I was only about five minutes away and was able to drop by to check her car for her. The battery terminals were after-market, the type that has two 7/16″ bolts that clamp over the bare cable end. These are a quick easy repair for the battery cable but sometimes they do loosen over time. That was exactly what had happened in this case. I was able to just tighten the terminals where they clamped to the bare cable ends and she was on her way.
A car that doesn’t turn over at all, usually has a battery related problem. Many cars are towed to auto repair shops every year due to loose or corroded battery terminals. If the car engine doesn’t crank over at all, the first thing to check is the battery and terminal connections. Here’s a quick auto repair tip, turn the lights on and try the horn. If the battery is any good at all this will be a quick preliminary check. If there’s no horn and no lights, try wiggling the battery connections. I leave the lights on while trying this so I can tell if I’m making a better connection when moving the battery terminals.
Still no luck? A load test with a battery tester is the next step after checking the connections at the battery. Many times a battery will show signs of failure by turning the engine over slowly when it’s beginning to fail, this is an early warning to have the battery tested. Unfortunately other times batteries will just fail with no prior warning. Temperature changes can sometimes reveal a problem with a battery that otherwise may go unnoticed. An increase or decrease of temperature will typically send cars in droves to the repair shop or parts stores with sluggishly starting cars. Batteries will need to have a good charge before they can be properly tested. Modern battery testers will indicate if the battery has a sufficient charge to be checked.
Alternators that are not charging properly can cause a car to have similar symptoms. It’s always a good idea to check the alternator to make sure the output is within the manufacturer’s specifications. The parts store or auto repair shops have the test equipment to check the alternator output for you. They will check the amperage, volts, diode pattern and check to see if the alternator has a draw or short that may be excessively draining the battery.
Starters can draw excessive amps or have an open circuit completely. After checking to make sure a good battery is installed, check the big cable connection at the starter which is the 12v one that comes directly from the battery. Then check at the starter solenoid (the small wire) to see if it is getting power when the ignition is turned to the start position. If power is going to the starter solenoid but the starter is not engaging, more than likely the starter has an open circuit or is binding. Sometimes the starter can be tapped with a hammer while the ignition is in the start position to get the car to start. This is basically to get the car into the shop for starter replacement. I’ve used this trick many times over the years to keep from having to push the car into my service bay. The starter can also be tested to see if it is creating too much of a draw on the battery. This can happen when the starter begins to to drag or bind and puts too much of a toll on the battery. The amp draw is measured with a battery and electrical system tester to see if it is excessive.
My tips and tricks have been picked up over the years with real hands on experience. Many auto techs don’t like to share their techniques, but I’ve been selling tools since 2005 and it’s time to share what I’ve learned during my time as a Master Automotive Technician. I hope my article helps many people to figure out what’s going on with their car and just maybe help prevent them from being stranded.