I’m unsure what issue I’m having with my car and I’ve been to different mechanics and have different work done but the problem seems to be persistent. The needles on my odometer board fall and dim when I’m driving(my ac,gas,and speed). Especially when I have my headlights and my ac on. If the needles fall while I’m driving, my board dims, all my needles drop, I can’t see how many miles is on the car, and if I’m driving like that long enough with the car like that my brake light comes on and the car begins to become harder too drive as if it’s shifting gears. There have been points where I could just be sitting in a drive through and my car completely cuts off and needs to be start with a jump now. I’ve had a new alternator, starter, and battery put into the car but the problem continues. I’ve been told it’s could be a loose ground wire or possible a fuse box or maybe something to do with the instrument cluster. I don’t know much about cars and not tryna keep throwing money into the car when it could’ve been a simple fix all along. If anyone knows anything and could let me know it would be greatly appreciated.
The BCM may be bad.
It sounds to me that something is causing a very heavy current draw, enough to overwhelm the alternator and drain the battery. Whatever that is, it ought to be getting very, very warm. I have never touched a working BCM, but I am guessing that it is not something that gets quite hot unless it is failing.
I suspect that the battery draining will occur even if the car is just sitting idling for the same time period. If so, that may help you find what is getting so hot.
I would also go back to fundamentals and re-check that the alternator is not flaking out once it gets warm.
You may have a faulty power connection somewhere. It may be with the ignition switch contacts possibly. You told us about the dash problem. Are there any other areas that dim or go out like the headlights or such? The more things you can find that are affected by the problem the more clues you will have to pin down the problem area.
The battery supplies power to the main panel under the hood first. Then that ties to the ignition switch and that turns on most of the power to the dash fuse panel. It would be nice if you could monitor the voltage to and after the ignition switch to see if the problem is there. I suspect it may be but there could be a bad connection in a connector also causing the problem.