Converters will last a long time if properly maintained. Keep an eye on incoming AC voltage, because if it gets too many or not enough volts it could cause damage to the converter or anything electrical that is turned on.
One way to troubleshoot a problem with your converter is to make sure that the polarity is correct. The wrong polarity will make the converter malfunction or not work at all. Aside from checking polarity, be sure to keep all the electrical connections dry, clean and tight. Always make sure that your battery is fully charged. Check your batter often to ensure it is holding a good charge.
If a problem does show up, consider it from all angles. Remember they will be bouncing around and vibrating while going down the road, and the converter could loosen from its mounting or the ground wires could loosen.
