SHORT IN DOOR LOCK/POWER SEAT CIRCUIT

[WFORich]

First time poster.  6 years into keeping my 1999 K1500 Suburban working and have a difficult electrical problem that has eluded a fix.
Lost power locks and power seats and found that the PWR ACCY 30A Breaker in the fuse panel (left end of dash) was tripping.  
Wired an old headlight bulb across (in place of)  the 50 A fuse underhood that supplies this breaker so I could try to find where the short was by unplugging things and wiggling harnesses. Unplugged  all plugs inside both kickpanels, under seat, lock relay etc  and short still there. Using an amp meter found the current going out the third wire (orange) in a straight connector coming out of the  "convenience center"  under the dash. This wire goes up behind the instrument panel area where I believe it terminates in a splice pack to divide it 6 ways that then goes out to all the door locks switches and seats.  I believe this mysterious "splice pack" is where the short is but wiggling  the harnesses up behind the dash does not even cause a flicker in my headlight bulb.  I have two options here as I see it:  Cut the orange wire  at the C210 plug coming out of the convenience center and rewire new wires to the 6 or so circuits it supplies or pull the entire dash assembly and steering column out and hunt for this elusive  "splice pack" .

Does anyone know the location of this "splice pack" marked S255 on the schematic?