This 10-second headlight test reveals battery health by checking if lights dim during startup, helping predict failures ...

Touch the red cable to the starter's positive terminal. If the starter cranks the engine, the problem is a bad chassis ground. Again, take all care in doing these tests to protect yourself. Or better ...

“It’s like saying, ‘I can’t justify doing an oil change.’” That’s how one exasperated mechanic summed up a baffling back-and-forth with a customer who just couldn’t decide whether to spend $400 to fix ...