Kenwood TK 7150
The external speaker hooks up to the 6 pin molex connector on the back of the radio. Looking at the back of the radio the pins go
Left pin column bottom to top, pins 1, 2, 3
Right pin column bottom to top, pins 4, 5, 6
Ignition sense is pin 1
Internal speaker - wire jumper in place pins 5 and 6
External speaker - remove jumper, speaker wires in pins 4 and 5
Pins 2 and 3 are for speaker output "B"
This is used for auxillary speaker when public address is programmed in software and switches to these pins when PA button is pressed.
All you would need are some pins from your local radio shop that fit the connector and the speaker