I'm going to start off by saying I am a forklift mechanic, so I have some background, i.e. I'm not ignorant

I own a 2003 Chevy Cavalier, 2.2L Ecoboost. I will list the issues, all symptoms, and diagnosis procedures I have used thus far.

The issue is intermittent, but has become a lot more frequent as of late. When I go to start the car, it acts as if there is no fire. Just cranks, that'* all. 9 times out of 10, the DRLs will flash erratically, the fuel pump relay will click on/off erratically, and a loud buzzing sound will come from the fuse box inside the car, (the DRL relay going nuts). If I can hear the fuel pump come on 5 times out of 10, the car will start, and 1 time out of 3, the car will die immediately after it starts. On some occasions, the car will shut off DURING DRIVING, and is a total pain starting again. And it may do that during driving a few times rapid fire, then works fine. I know that if I don't hear the fuel pump come on, it WILL NOT START! At one time, I closed the glove compartment, and the car shut off (lol). The instrument cluster goes crazy as well. When starting the car, all the gauges drop underneath where they normally ride, indicating an electrical issue.

Now for my diagnosing procedures thus far.

I have correct fuel pressure in the system. I'm getting fire. The fuel pump is ok. All relays are good. Engine grounds have been cleaned and reattached. All fuses good. Aftermarket radio has been rewired to ensure no issues there. Checked the harness going to the fuel pump, all ok there.

My thoughts : I strongly suspect the BCM to be the problem. It controls everything that is listed as a symptom. The instrument cluster going nuts also points me in this direction. I'm not sure how to diagnose the BCM, since I'm sure GM is the only one that knows the test points. Does anyone know where to back probe the BCM and the voltages to look for? Are there grounds for the BCM underneath the hood?

I may have missed some things, but feel free to ask questions if further info is needed. Thanks ahead of time for the help!!!

Lately, I've wanted to do this ---> to my car.

Your symptoms are really pointing to the classic bad battery or poor connection at the battery issue. Considering its intermittent, I suspect a poor connection.

Battery has been replaced with a higher CCA battery. All grounds have been cleaned and reattached. Nothing classic about this one.

i would guess the ign switch. it supplies power to all that and for it to just quit while you are messing around in the glove box its got to be something inside.

But wouldn't that cause a more extreme issue? I still get power to the instrument cluster........

I think Justin may be on to something. My 2000 Blazer would do pretty much the same thing as yours did. These ignition switches use a finger blade to make contact with another finger when the key is turned. Carbon builds up because of the current load arcing between the contacts.

This is EXACTLY what happened to my pontiac sunfire that i had for racing. Check your battery grounds, in my case I had the cables on the battery this battery was grounded on the engine block and on the battery tray, one wire obviously to the starter. It was a strange setup because all these wires branched off the cables. Now the ground on the battery tray was rusted all to hell and when trying to start the car the cluster would do all kinds of wild things, the fuel pump would hum, there were crazy sounds coming from the fuse box. So what you have going on sounds like some bad grounds so check all of your cables and wires relating to the battery because from the sounds of it thats exactly what happened to my sunfire.

Agreeing with Justin on the IGN switch, I have heard of similar symptoms to this, and it was the IGN Switch, I'd inspect the switch, and the wring connector.

while it is acting up you might take a test light to the fuses and find that the light is not as bright as it should.Remember 12 volts not not mean it can carry a load.Ignition switch is the first suspect on my list.If it is ok check the ground below the battery also inspect wiring harness near the battery they are known to have problems in that area