1994 fordvmustang

Hi,
You spliced the harness & bypassed the Plugs? Whether you or another did is immaterial, best thing to do is buy the plugs & do a proper plug-in install.
Do you have the Ford premium sound system? if so, you need the premium sound harness, not the stock harness. it should have (2) independent plugs, a power harness and a speaker harness.
Depending on the system, Blue/Wht is the remote trigger for the AMP....or a right front speaker (+). There’s a light blue wire that’s a left rear (-). Then there’s the possibility you shorted out the keyless entry system.
I’d not worry, it is what it is- Lots of information available in the Stangnet archives on this, another quick reference below. I’d suggest pulling your fuses & seeking out blown ones, undoing what triggered this, look for any other wiring that may be affected/shorted- first.
Disconnect your battery for a few & reconnect. Keep a door open or window down so it can’t lock you out, as a precaution. Has function been restored?
https://www.the12volt.com/installbay/stereodetail/893.html
Good luck!
-John