I'm posting this for the sole purpose that it may help others with a similar issue...
Electrical Short Subwoofer 12v
Supply Wire FOUND and FIXED
I carefully disassembled most of the interior of the coach - traced the short to the lower rear sheet metal screw that holds the road side low hand pop out vent interior plastic trim ring in place. That screw was driven right through the cable bundle, shorting the black and blue with white line wires (black is subwoofer power and blue with white line is radio amp control).
I thought I would pass this on in case others experienced the same problem.
A service manual on how to properly disassemble the roadside seating areas would have been helpful, but thankfully I'm a skilled cabinet maker, sheet metal worker, and automobile restorer, and so I managed.
I invested the better part of a week of labor to fully disassemble, diagnose, repair, and reassemble everything. This of course was extended since I had never worked on an airstream before nor had any reference drawings or manuals to work from...which would have greatly shortened my effort.
PLEASE sell me a service manual??!!
I found the build quality of the airstream generally good other than the mis-placed screw / cable - however I highly suggest you consider running your circuits in conduit - with the life span of these units and the likely need to replace or re-route wiring and other control lines in the coach over the next 20-30 years - it would be useful to be able to do this w/o having to drill out interior or exterior rivets just to get to the wire looms - a few hundred feet of well laid out conduit would not only make running circuits a breeze (including repair and rewiring), but it would not add much weight nor much cost. I would happily pay a few thousand extra to cover materials and labor to have ALL the wiring in conduit and ALL the circuits in proper sheet metal control panels (not just plywood panels). Perhaps I would execute this upgrade if / when I ever were to restore the coach...
I hope Airstream would consider this for a future model - offer it as an OPTION so as not to drive up cost on everyone - unfortunately, now that I've been through and through the coach - it will probably last 10 or 20 years until I can get a new one!
Other FIXES that I completed around the same time:
- one of the rear hinge nuts had come loose from the long screw that holds the middle rear hatch hinge in place - this is located inside of a C-channel accessed by removing the rear screen assembly (the whole thing that goes around the rear opening - not just the screen part) by removing the screws on the side and the screws hidden behind the black plastic hole plugs along the top
- I installed a 20A switch above the radio to turn off power to the subwoofer so as to save battery life when listening to the radio or a movie when not plugged into generator or shore power (this is an upgrade, not a fix, but was only made possible by the extensive line tracing required to fix the subwoofer power short problem in the first place - since I had wire access near the radio to that black hot line - I installed the switch - the wires run up the wall and over the radio behind the insulation...mine had fallen away from the outside of the coach wall - so I just used the slack to route to a switch and back up behind the insulation)
- I fabricated a new shower drip shield to deflect water away from the opening beneath the door - the original thin clear plastic seal was totally shredded and not blocking any water - the clearance was not uniform and very tight at the latch side - making it impossible for that little gasket to survive for long - raised the shower door 1/4" to get clearance for a new deflector / seal made from a door sweep - if you are interested in this I'll have to send you a picture - too hard to describe - but it was a custom fabrication situation - but works 100% leak proof now
- Connected second TV set HDMI - that was disconnected when I received the coach - now all TVs can play through stereo as designed and "All OFF" AnyNet functionality works - but turned it off on bedroom TV so TV stops going on every time we want to watch a DVD in the main room...
- Repaired outside fender covers - "bent" support out at each end away from trailer body - which better holds covers in place (after removing and cleaning pounds of dirt / sand from each end of each side...) - re-caulked with a much larger but streamlined 100% silicone bead for each RS and CS fender - then set two rivets in each end of each fender cover WITH a washer to distribute load against plastic fender cover - rivet goes through AL support bracket which is a V bent and screwed to coach from the outside before setting fender on...
- Had to bend back the brackets for the fold out leg on the CS fold up dinette side - leg was unfolding "too far" and ended up loosening the 3/4" face board - which I CAN NOT get to w/o removing the 1/8" plywood that is pressure-taped all around to the bottom of the AL inner support frame - so I can't repair it w/o destroying it (no access to tighten from the inside) - so I just drove three large cap-head sheet metal screws straight through the face into the AL frame below - good purchase into the frame so everything pulled tight - but now I have those exposed screw heads - not ideal
- replaced one missing rivet in the interior (minor issue)
- reset gaskets on fantastic fans that had come loose (minor issue, but important to fix!)
- cleaned garbage (both debris from assembly / fabrication and a few wrappers) from all of the nooks and crannies I exposed through my extensive wire tracing
- one last item NOT YET FIXED is my zipdee awning - the tube assembly is too long or the brackets were set too close together - b/c when I close the awning up and secure one side (can be either one) the other one is about 1" too far outside of the "securing wheel" that is to sit in the recess and secure the awning for travel. I have managed to angle each assembly enough to get purchase of the recess and be able to travel with the awning secured - but in a coach of this caliber - this is not acceptable - and since I'm limited to a vertical strut for the placement of the awning ends on the coach side - I'll have to disassemble the awning tube ends and see if I can manually shorten the offending end - so the support arms will sit vertical and plumb and BOTH "securing wheels" may FULLY seat in their recesses and properly secure the awning for transport. If anyone has information on how to do this or if it can be done - please email me at firstname.lastname@example.org