88 4Runner SR5 Rear Speakers

Just bought an 88 runner and hooked up new head unit to stock wires. No sound. on investigation founf someone had cut the wires to the deck (rear) speakers and removed the factory speaker plugs. Here is the problem- the speakers (OEM?) appear to have amps built into themas they have 5 pins and say 12volts, 4 ohms. Any ideas as to how  to reconnect these cans or should I just dump them in place of aftermarket hardware?  (I have the same speaker in my 87 and they sound good to these old ears.)

Thanks!

Jack