What kind of electrical problem do I have?

Since you changed batteries there is a chance you did not get them actually connected correctly and they are not back online and charging. The converter could be developing some issues or just getting hot inside the compartment. Open the compartment and put your hand on it carefully. If it is hot listed for a vent van running. I went inside my compartment last evening for something and noticed it was hot in the compartment and the fan was not running. My little button thermostat had failed for the second time. Bypassing it with a small jumper until a new one (with lower temp activation) arrives.

As suggested, starting at the batteries with a voltmeter is where I would go first.