I have replaced several sensors, coil, alternator battery. My car misfires when cold, the rpms jump and it almost stalls when accelerating. Now the lights dim and the battery light come on. The alternator was tested and was good. This is driving me crazy. I would appreciate any input. Bcm? I tried another ecm and that didn't fix the issue.

I have a motor with 15xxx on it new battery and alternator. Starter is only a year old. This is the 5th alternator and 3rd battery. I have checked the wiring harness and have found no breaks anywhere. My battery keeps dying every 3 days or so after a full charge. I do have a system in the car but the battery i had before this new one handled it fine never had issues like this. The dash and headlights dim lower higher when accelorating and the heat guage bounces up and down well i drive. But the heat stays the same temp. Something in the car is draining and I can't figure it out.

Also I can't seem to find any ground wires on the motor itself. If I'm right there should be one from top of motor to frame. Transmission to wiring harness and one from bottom of motor to firewall. Would not having these wires on there cause any of these problems?
Any answers would help.

All I was doing is changing front brakes and this happened..i dont understand why? Is it expensive to fix?

overheated and wont start what now?