Today I need to put some MC4 connectors on the cable of some new solar panels. This is a video of what I have found works well for me.
This application is low voltage (12 to 24 volt) to run a DC brushed motor water pump.






WARNING: Solar panels generate electricity. Electricity dangers include: fire, shock, burns, and electrocution.
Soldering carries risks of poisoning, burns, shock, fires, etc. If you do not know, learn first or do not do this.