I've had some dashboard electrical problems (tach and gas gauge sometimes don't work with the headlights on) so I'm devoting time to it. I've been wanting to update this cassette / radio too. I pulled the radio out. There was something behind it. A small amplifier? It was not secured. It's just hanging loose behind the radio. Also, there was an ON-OFF switch stuffed back there. Looks like a Ford switch. Wrapped masking tape made sure it was ON all the time. Someone spliced in heavy speaker cable, as if a lot of watts was running through it, to some speakers. Those cables are now marked Left-Front, Right-Rear and so forth.... Perhaps a radio / speaker installation was later removed, and OEM stuff replaced? Anyone know what that "amplifier" actually is? Can this radio live without it? How many watts per channel does this radio have? And what is the On-Off switch for exactly....?