Dim Lights

Here's the point that you are missing... Your cars entire electrical system is weak. Dim lighting is the only visual indication ( volt meter for dummies LOL ). Don't take that personally 'cause you're just one of the crowd of owners who don't or didn't realize how much better everything about the car could work if it had the full 12 volts required.
So replacing every light bulb in/on it with LEDs wont get better start, run, fuel mileage, wipers, etc...
This forum can brighten/enlighten the space between our ears.
The madelectrical bulkhead/amp gauge bypass isn't required to fix it either. All that really does is move the factory engineered point of failure to some other locations under the dash. It all worked just fine when it was new so with proper repairs it can again .