How do you test spark plug wires?

Spark plug wires can go bad in several ways. They can develop shorts, or they can just build up resistance. To test for shorts, go out at night and open your hood and let your engine run. If you see little flashes, or hear pops, you probably have cracked wires that need to be replaces. To test for high resistance, you need a multimeter that can test for ohms (the resistance between two points.) You take off the spark plug wire and touch one probe of your multimeter to one end of the plug wire, and the other probe to the other end. Normal plug wire resistance should be 10,000 to 15,000 ohms per foot of length. If it is higher, it is probably bad.