I believe the box can be taken out with a 15mm deepwell socket.
Unplug the wiring harness going into the drivers side of the amp mounted on the box. Remove the nuts that are recessed in the bottom of the box, i think there are 6. You'll know when you have em all, it'll drop right down giving you full access to the 6x8's.
Its in the trunk, in between the rear speakers under the trunk lineing.
According to http://www.installdr.com/Harnesses/GM-Wiring.pdf the connector for the rear speakers is separate from the front speakers. If the connector for the rear speakers is loose or disconnected, the rear speakers would not work while the front ones will. The amp in the head unit (dashboard radio) powers the front door speakers. The rear door speakers and roof (pillar) speakers in the rear are powered by a second amp under the drivers seat. Either this amp is bad or is not hooked up.
In the trunk. If you have a full size spare, you will need to remove it. Typically the amp is behind the matting that covers the top portion of the "trunk cubby". (directly underneath where the rear speakers are located) you will see a long black plastic housing. The sub and the amp are attached to this. Amp is on the left and mounted from the top.
lincoln has a standard radio which has a booster amplifier mounted in truck behind carpet of rear seat. there are no power amps like bose in each speaker it just boosts stock radio output from amp to speakers
Yes but you have to re-wire all the speakers
It could be a combination of wires and the amp, but I would start with the amp.
The amp is on the roof of the trunk compartment, right behind the seats, and in between the two rear speakers.
The Amp is located in the trunk below the rear dash
there is no subwoofer in the 93' mark 8 only 4 5x7 speakers and 2 mids. and an factory amp located under the right rear tail light
Hook your speakers up to the amp.
In the one of the cubby holes in the boot, its in the sub plastic box.
The amp is right next to the subwoofer. They are both located behind the rear driver side panel.