No Power in the car, but there is in the engine bay

I was planning on doing the 60 amp alternator upgrade because if the speakers and msd, so that's why I was thinking about the ammeter bypass. But yes I checked every connection several times and they were all tight. I took off the bulkhead connectors, used a wire brush on the terminals to clean off any corrosion or debris, and used compressed air to clean it all out. I left the doors open and with the battery connected, I touched the steering column to the floor and all the lights turned on.