I am fairly sure I understand your problem and I believe it is a poor design issue. First though I need to verify some things:
1) You have a 38J so the actual page numbers on the TV/DVD wiring diagram (http://www.winnebagoind.com/diagram/...ire_156326.pdf
) are pdf page 2 and 10 (Sheets 1 and 9) not page 11 as John said on the other site. FYI: Here is the TOC page for your wiring diagrams: Table of Contents
2) The parts book for your rig (pdf page 120; http://www.winnebagoind.com/service/...07/7ipg38j.pdf
) says you have a Sony model 27FS120 TV. On pdf page 13 of the TV operators manual (http://www.docs.sony.com/release/KV27FS120rev2.pdf
) it says Component Video (Video Input #4) has 5 connections (Y [green], Pb [Blue], Pr [Red], L [Audio Left], and R [Audio Right]). Video Input #1 has a seperate input (v [video], L [Audio Left], and R [Audio Right]). This design is where I beleieve the audio problems come from because the Winnebago engineers did not interface it corrrectly. Reffering to pdf page 10 of the Winnebago wiring diagram above, you will notice the Composite Video (Y, Pb, Pr) connects to Video 4 but the only audio is routed to Video 1. That means no audio is being supplied to the Video 4 channel.
3) The parts manual (pdf page 120) also indicates they used 3 different DVD/Home Theater/(VCR) units (SONY HTV700DP, TOSHIBA SD-V57HT, or MEMOREX STS71E-R). On page 12 of the the Sony manual (http://www.docs.sony.com/release/HTV700DP.pdf
) it says the DVD can only use the composite video output. The Sony unit only has the one set of Audio outputs (expecting the TV to use the one set for either video type) but the TV requires seperate audio inputs. DVD output is over Composite Video (Video 4). Reciever (VHF/UHF/CATV Antenna) video is over Video 1. Please note that all Control Center input is over the UHF/VHF Coax cable on th rear of the TV.
There are 2 seperate solutions to your DVD audio problem:
1) For DVD or CD operations, the Sony player is basically designed to use the Home Theater system for audio rather than the TV speakers. You should adjust the Home Theater Volumn, not the TV volumn.
2) You could puchase a couple of Y audio adaptors. At the TV end, the base of a connector would connect to the cable from the DVD/Home Theater system (i.e Left audio). One branch of the Y would then connect to Video 1 Left, the other branch would connect to Video 4. This way both Video 1 and Video 4 would have an input.
One final note. You can route the audio from the TV to the Home Theater AUX input (surround sound), The TV menu selctions provide for two seperate Audio mode selections. Either the volumn can be adjusted by the TV remote (Variable) or by the Home Theater (fixed). Just make sure you know which TV audio output mode you have it set for. The operators manual for your rig (http://www.winnebagoind.com/resource...Suncruiser.pdf
) says to use variable.