Yellow to battery, Red to ignition, Black to ground, and match the speaker colors. Do that, and this old Kenwood will fire right up.
Don’t panic. Here is the standard color code for the Kenwood KDC-MP333. Kenwood has historically been very consistent with their color coding. For the KDC-MP333, here is what each wire does: kenwood kdc-mp333 wiring diagram
Have a wiring question about your specific car model? Drop a comment below and I’ll try to help. Yellow to battery, Red to ignition, Black to