Generally, the leading wire of the left box corresponds to the negative pole, and the right side corresponds to the positive pole, but this depends on whether the module is placed vertically or horizontally, so you must look for the laser-engraved marking next to the cable gland of. Generally, the leading wire of the left box corresponds to the negative pole, and the right side corresponds to the positive pole, but this depends on whether the module is placed vertically or horizontally, so you must look for the laser-engraved marking next to the cable gland of. How to Check Solar Panel Polarity (Reverses + Fixes) - Solar Panel Installation, Mounting, Settings, and Repair. A solar panel's polarity is essential when installing or replacing a solar panel. Solar panels are polarized to generate more power during the day, but if your system is not set up. Yes, solar panels do have polarity. But fear not – today we'll turn you into a solar Sherlock, complete with multimeter magnifying glass and MC4 connector clue Ever tried assembling a DIY solar array only to realize your. How to prevent DC polarity reversal Do not use one color cable for the positive and negative string. Red is the positive cable, and black is the negative cable.