OBD1 Error code 41

Hello,

41 An open or shorted condition detected in the generator field control circuit. You need to replace your alternator this guide will walk you though the steps.

https://www.2carpros.com/articles/how-to-replace-an-alternator

Please run down this guide and report back.

"Charging system circuit not responding to control signal".

I've never run into that code, but I'd start by measuring battery voltage while the engine is running. It must be between 13.75 and 14.75 volts. If it's low, measure the voltages on the two small wires on the back of the alternator. That must be done while the engine is running.