Electrical drain while the car is running

I noticed that my voltage was spastic going higher and lower while driving. I have a good battery, a brand new starter and have just replaced the alternator yesterday. however there is still a drain on my battery. last night the voltage dropped to around seven and the car did not want to shift or drive. I also lost power to my radio and then the car shut off. I left it in a parking lot over night and went back to get it today and it started right up but the voltage was dropping as I was driving. the lights on the dash are as follows: door ajar (with no doors open), battery, SRS (airbag), and parking brake. these lights do go off for a second when I start to drive but then come back on after a second. please help.

Something I read on a forum said it could be the electronic load detector but Honda dealer said I would have to buy a new fuse box for under the hood. However I watched a couple YouTube videos that showed how to change the part in the fuse box. How likely is it to be this issue?