My lights Pulse /flicker, inside and out the.

Usually when you have electrical lights flickering, it suggests that there could be a short, some lighting connections that are lose and there also might be a power surge for some reason or another
You will have to trace down the issue. I use the Haynes Repair Manual for my vehicle.

Go to your local AutoZone and order one.
They tell you everything about your vehicle that you will want to know about and how to fix this and that