Troubleshooting A Power Center Converter That Isn't Recharging The Battery  

Hi - my 5th wheel has a Parallax series 500/model 500 converter that just started blowing the two 30A polarity fuses in the middle of a trip. Ive done some diagnostics on it have electrical knowledge but not engineer-level, and hoping you might be able to confirm my suspicion that I have a dead short, or the converter is otherwise bad and needs to be replaced. Some context: - Two newer 12 volt deep cell batteries in parallel. Correct wiring, pushing 14V at battery same voltage observed at the panel. -110V AC shore power works fine -Battery is NOT charging when connected to shore power -All 12V DC accessories work fine until battery dies observed while connected to shore power - All AC circuits are working. -If I connect a battery charger to the batteries and plug into shore power, I can maintain proper charge. -Each time I put a 30A fuse in, it immediately blows both blow, when connected to shore power OR disconnected from shore power/battery only. This happens with no accessory load everything off and even disconnected/fuses removed. -No shorts in any individual 12V accessory circuits observed after disconnecting all fuses and cutting power -No shorts in 12V battery supply lines observed after disconnecting lines from converter/cutting power -**With converter isolated and only grounded ie, all 12V DC fuses out, all 12V DC positive wires disconnected, I have CONTINUITY/closed circuit between GROUND and BOTH 30A DC polarity fuses** That last point makes me think I have a dead short or something bad within the converter. Would there ever be a closed circuit on these polarity fuses and ground on a functioning unit? I appreciate your brains on this one!

asked by: Doug