Yeah, I wanted more light on the back as I think the tail lights alone are not enough. I am a big fan of being lit up at night. Not worth the grief of heavy modification though. I will look for an alternative such as a bumper mounted strip etc.
I did just replace all my interior bulbs with LED's and they are extremely bright. It is like daylight inside the jeep when the doors open.
PWM is the best way to dim the because it can be changed in real time to adjust to the brightness that you want, but adding a resistor to the power supply would also work. sounds like you are wanting a dimmer "running light" but then still want full brightness with the brake press? not 100% certain if this will work or not, since our 3rd brake lights are not just simply a light strip with 12 volts running to it, but in my mind it should work. the way I see it you have a few options but 2 main things to think about.
1st up is power. if you dont mind the 3rd brake light "running" all the time while the vehicle is on simply find a power wire that is not full time, splice into it, and run a secondary power wire straight to the light. If you only want it to run while your other lights are on I would suggest splicing into the tail lamp wire or other wire that only has power when lights are turned on.
2nd up is dim method. once power source is determined you need a way to make this the dim power while the normal supply to the light is the bright power. Like i said earlier, you could simply add some resistors in line with this new power wire, to limit the current, which will limit the brightness. not sure how many resistors or what size will do the job, but they are fairly cheap and you could get some off of amazon and play around a little. the other option is to get a 12v dimmer switch. again these can be purchased from amazon (here are two options with remote
or without remote
). the remote one would allow you to hide everything and still be able to adjust, while the other one would not (depending on mounting location). I have used both of these (mot these exact ones) in some LED nightlight/lamps that i make and they both work great. They will hold whatever setting they are set on even if power is cut.
So what you would have is a full power and a dim power going into the light. the dim power would operate when brakes are not pressed then when brakes are pressed they would light up like normal. Again this is just a theory, but figured it might be worth an $8 dollar investment to you.