When you replace your alternator, it's a good idea to replace your serpentine belt at the same time. Your technician will have to remove the old belt anyway so he might as well put on a new one when he's done. And the number-1 alternator killer is a battery that's on its last legs; the alternator has to overwork to keep it charged. If your battery is 5 years old; ask your Phoenix technician if it's time to replace it. At National Automotive Repair in Phoenix we install quality NAPA replacement parts. Give us a call at 602.978.3278 and let us help keep you on the road.