Installed a powewr inverter for my DVD, however when i roll the window down, the inverter cuts off. Recently my keyless entry has stopped working. Dont think im using to much power. Was thinking about getting an Optima battery (which i shsould have gotten at first). But does anyone have any suggestions so that something else doesnt "die".

What i have hooked up to the car:
Autotek Amp (maybe 200 watts)
Playstation (maybe 75 watts when on) Only thing hooked up to the power inverter.
FM modulator
AVeletronics Module

8 gauge wire to distribution block into two 8 gauges going to inverter and AMP. Fused with a 60.


Also is there anther way to upgrade the firmware outside of shipping my unit so that i caan get rid of this fm modulator.

 

It sounds like you need a larger inverter. Most inverters (especially if being used close to their potential) will shut off w/ a drop in voltage. This will be more noticeable if the car is not running.