Need 300m help!
 

I have a 1999 Chrysler 300m, I recently have had some electrical issues that I am not sure wdwoult hy they are going on. I have aftermarket auto start/keyless entry on the car. Problems started when we would push the unlock button and it would not unlock, we would have to push 2 3 times before it would unlock. Well now it will not unlock at all, and the car is chiming on the inside and the lights are flashing on the inside. The car will start but the headlights will not come on at all. Also the gas gauge reads completely empty when I know that it is not. Also the check engine light is on but when I checked the codes it said auxillary emissions control. p1945 or something. Ao I removed the aftermarket alarm brain and the car still chimes and the lights flash on the inside. Any help would be greatly appreciated