A voltage multimeter can be quite handy when troubleshooting a problem with your light bar. It can help you determine if your lighting device has proper DC voltage, check continuity, and measure voltage drop. This comprehensive guide will walk you through the process of using a multimeter to test an LED light bar, ensuring you understand the underlying principles and can effectively troubleshoot problems. Pop the hood and check your battery for the following: Age of battery: How old is your.