Low beam headlights not working

Couple questions. First, we need to make sure you are using the correct bulb because you have a control module within the smart junction box that is responsible for turning both lights on. A lot of times when we use the incorrect bulb, such as an LED, it will alter the resistance and the module will not be able to determine if the lights are on or not and it basically gets confused.

So let's try unplugging the new bulb that you just installed and then see if the other light starts operating again,

If it does not then we need to check voltage coming out of the SJB on these circuits. If you don't have voltage then I suspect the module has failed.

Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-wiring

Let us know what you find and we can go from there. Thanks