I need to find out what transistor values they use for a JL Audio e1400d monoblock amplifier

12 g

Check for a speaker wire that come come of , Or a loose grond wire on the amp or where ever you have the ground wire connected two,

Due to the power required for most amp's, Most people place either an second battery in the boot of the car or fit Capacitor (power cap)
Which will then allow amp to consume the required power without making main power for the car drop.

Loose wire or connection is causing stereo to short out, Check all connections including amp,Stereo,Speakers and make sure nothing is touching places it shouldn't

the ones directly across from the burnt ones is the same value

It indicating that the power output is too loud and possibility of speakers may get damaged if played at this volume for long periods. When the loudest sound is played the led light mightshow its loosing its brightness and dims in time with the sound level.......................sodeep

You need the old transistor. Knowing it's brown is not enough; you need to know its resistance value. It sounds like the resistor you replaced with has too low a resistance value, causing the "cuts" in sound. Find the old resistor and then use this site to find out what you need:

http://www.dannyg.com/examples/res2/resistor.htm

jl audio is a good name to stand by for amps kickers amps sound good at a high vol but not at a low vol

The audio amplifier IC´s maybe are fried

there is a short check all connections carefully.. im betting it is your speaker connections