Buzzing noise after recharging dead battery

While replacing a leaking wheel cylinder on my 06 Tundra my battery went dead. I began to charge the battery and immediately a buzzing noise coming from the passenger side wheel well(?), that I assume has something to do with the ABS(?) So, I disconnected the battery cables to prevent any damage, then continued the charge.
When I reconnected the cables, the buzzing continues. So I wait one day, then two days and reconnect the cables again, still buzzing. I disconnect again.
We did bleed the brake at this wheel and kept reservoir full. Could this buzzing be getting fluids recirculating or could it just be a bad part?
Any suggestions or advice is greatly appreciated.
Fred

 

Have you put pressure on the brakes while its buzzing?

 

No sir. Trying to do this alone, so didn't think I had time to do anything but disconnect the system before any damage. If you are suggesting that may stop or help with the buzzing, I'll definitely give it a try.

Thank You
Fred

 

I dont have a clue. If you get it to buzz again, feel the abs unit & see if you feel vibrations?

 

Is the noise from the rear wheel well area, or front? If rear, I’m thinking it’s the pump running for the EVAP leakage test.