Posts: 2752
Location: Mauston, Wisconsin | It sounds like you have a connection problem or one of the batteries has a cracked inter-cell weld. That can happen because of vibration from running in rough water or the weld was faulty from the factory.
FIRST: Carefully check each connection, starting from the batteries moving toward the trolling motor. A simple visual inspection is not good enough. Take off the battery/cable connections and make sure there is absolutely no corrosion, then reattach and tighten them properly as you go forward. Be sure to leave one of the battery connection's disconnected, preferably one of the ends of the jumper that connects the two batteries together.
Check the connector pins, both on the receptacle and on the plug. Then take off the TM cover, and check the connections there w/ TM unplugged.
If its a intercell weld problem you may only need one battery. The way to find the bad battery is to check each battery's voltage when its under load, i.e., when the TM is acting up. Obviously its hard to do w/o a partner. The bad battery's voltage reading will be much lower than the other good battery.
How old are the batteries? If you have access to a good battery. You could also replace them one at a time w/ the spare - known good battery.
Good luck.
Al |