Bad ground wires are usually attached to an accessory or engine component affected by a symptomatic electrical glitch. If the ground wire is loose, it may need to be reattached firmly; if it appears attached, a voltmeter can be used to locate breaks inside the wire's cladding.
Fuel pump malfunction, audio issues and many other electrical glitches in automobiles have to do with ground wire issues. However, the abundance of wiring in modern vehicles can make faulty or loose ground wires hard to find. If a ground wire problem is suspected, the grounding connection between the accessory or engine component and the vehicle chassis should be reattached, ensuring the attachment area is rust-free and clean. A voltmeter can help determine the position of an internal wire fault by measuring current carried in the wire.