Car fuse box purpose The sole purpose of the fuse box in your car or van is to protect every electrical circuit in the vehicle. There are a number of circuits in your vehicle including the main computer,the engine,the transmission as well as components such as the lights and windscreen wipers. How to Replace Your Vehicle's Fuse Box - Autobutler blog Is this answer helpful?Thanks!Give more feedbackThanks!How can it be improved?How can the answer be improved?Tell us how How Fuses Work Explained in Under 5 Minutes - 2CarPros A fuse is designed to blow in the event of a circuit overload stopping the voltage flow. Most power distribution centers are located under the hood or dash. Heavy duty fuses are used to supply voltage to sub electrical systems which then power many smaller accessories. Use a test light to check a fuse condition. If a blown fuse is discovered replace with equal amperage rating. Car Fuses and Fusible Link Colors and Functions Explained There are six types of blade fuses that you may run into when you pop open the fuse box on a modern car or truck: micro2, micro3, low-profile mini, mini, regular and maxi. For all blade fuses, the housing may be opaque or clear.