Volvo Repair: Volvo 780, sway bar links, rear sway bar

Question
QUESTION: I just acquired a quite nice 1990 780.  The only issue with the car is the rear suspension.  The left rear side is lower than the right rear.  A major cable is disconnected at the battery and a major cable (red) is cleanly cut at the left rear wheel well.  Any past discussion links or advice will be appreciated.

Jack

ANSWER:    Jack, I'm going to guess that cable was for a "thumper" stereo amp. that has been removed.
   The suspension should be inspected but I would venture to guess you have a broken spring. Also check the rear sway bar links.

Mark

---------- FOLLOW-UP ----------

QUESTION: Mark, thanks for the prompt response.  The cable at the battery is part of the original wiring of the car, and there is no evidence of additional speakers being installed.  I heard something about the Bertone's having a special leveling suspension and I thought you might be familiar with it, if indeed it has this feature.  Thanks.  Jack

Answer
 Oh, it's a Bertone. Yes it may have and been disconnected because of high cost to repair. @ $ 1500.00 a strut. Two things. Most shops converted them back to conventional suspensions as they failed with used yard parts. They may not have relaced the rears because they were still "holding" That one may have failed now allowing the vehicle to sag.

Mark