vandal968

If you've removed the Bose amp, then you don't need to connect the MOST cables. They connect the head unit, amp and cd changer.

cheers,
c

DUTCH8

Thanks vandal. I did not remove Bose amp, it was never there. I guess the MOST is present because of Navigation & Phone module, these functions will be done by the new Android headunit. So I was looking for confirmation that MOST can be ditched/ignored.

bl79

Hey guys, took a gamble and snagged a 9" Android 7.1 unit from ebay w/ MOST adapter.

Took a bit of care to figure out what goes where (and I still have an unused plug) but I got everything wired up and it was working great...for 10mins. Then the audio died and now when it's on I get this odd thump from the speakers every second or so. Otherwise the unit appears to function fine (and was working before it shat the bed). I plugged in the OEM unit briefly and confirmed everything still works as normal.

I'm thinking the MOST adapter is probably dead? Either an infant mortality or maybe I wired it wrong? Battery + and ground I spliced off the main Android harness and I'm certain those are correct. I saw a post stating to wire the "acc" wire for the MOST adapter to the "amp con" wire (part of the "RCA Harness" that the MOST adapter plugs in to). I did that and everything worked pretty well but if incorrect would that cause the failure? I don't really see why continuous 12v (or 5V or whatever) would kill it like that. I then checked all the OEM pins and I couldn't find anything wired to ACC position anyhow...?

Any tips on where to grab ACC power from? Ideally I'd like to not splice the OEM harness but it's not a big deal I guess. I'm hoping the seller will refund me for the MOST adapter. Then I need to figure out where to source another one. I'd be willing to pay a small premium for a good unit but seems all the options are either a gamble or like $500+. Big thanks to the trail blazers in this thread. I'm hopeful once this stuff is resolved it'll be a nice unit (aside from my iphone not auto-tethering....)

Hal 2000

bl79- Try connecting a cell phone playing music, directly to the most adapter, with a 1/8" to dual rca adaptor cord, to see if you get sound. Most adapter initial failure is common. This is the first thing I did before installing the actual unit.

Zakowsky

Bl79, test it for sure, but maybe it has something to do with the order the HU and the adaptor power up. Could be the MOST adaptor needs a signal when it starts to work correctly (or the opposite). Btw, which unit did you buy? It would help to keep track of which ones have problems...thanks.

CaptainGSR

Deleted because erroneous info...

Zakowsky

I'm surprised CaptainGSR - as you have the system not doubting, but it is strange that in the picture bl79 posted there is a brown plug going into the middle port, which is the direct to speaker output. I have the PCM 2.0 with Bose (so MOST only) and I don't even have a plug for that port. I wonder why it's connected?

CaptainGSR

Yeah, you are right. I am looking into that now. I might be completely wrong. He might not have an amp. Then he would be fine.
I won't be home for 2 more weeks, so I can't pull my PCM out to verify for sure.
I do not have the Bose option. I do have two dash speakers, and two more speakers in each door, for a total of 10 speakers (no sub)...
I will edit my previous post if i am wrong. I have option "8RV" on my option's list (trunk sticker).
Cheers,

Shawn Stanford

I have a non-Bose system in my '05 and I think the MOST connection was just for the information display on the dash. That's not connected in my setup, and the steering wheel controls are going through an adapter. I have a nothing-special JVC and it was a simple VW connector to JVC connector.

bl79

Thanks Hal 2000 - talked to some EE buddies as well and they recommended a few similar ideas. Here's the scoop:

• Porsche original stereo still works fine when plugged in
• 3.5mm Ipod input to RCA to the MOST adapter does nothing. Thumping sound continues with no change
• 3.5mm headphone output directly from head unit (i.e. cutting out the MOST adapter) I can hear stereo sound functioning correctly. It's just quiet/unamplified
• Probing all incoming Porsche factory leads I see no 12V accessory wire (04 CTT w/ Bose system)
• Confirmed I wired my MOST adapter correctly (assuming ACC needs 12V....)
  • Yellow wire is constant hot 12V, black wire is ground and the red "ACC" wire is tapped into a 12V lead that is tied to key in ignition (this wire comes from the "RCA" harness supplied in the kit)

So given all that, unless the MOST adapter needs a switched 5V or something (which they probably should include some sort of instruction....) then I think everything is right and the MOST adapter is just infant mortality. Seems pretty likely given the responses in this thread. Amusingly mine has a sticker saying it's for Mercedes. I'm sure they all come from the same Chinese factory.

Anyhow I got a 9" Seicane clone from "Automagnitola" on ebay. The unit appears to work fine (knock on wood) but the MOST adapter is dead. I'm going to send him pics and explain the above and see if I can have another sent. Otherwise I'll initiate a paypal dispute. Not trying to ship this back for 20$ either considering it probably costs a few dollars to make.

This is the unit.
https://www.ebay.com/itm/9-Android-7...53.m2763.l2649

It seems to work and comes with all the fixins. Aside from the MOST issue I'm pretty happy - then again I came in with the mindset that I was buying cheap Chinese hardware so that probably helped. The viewing angle picture is a bit disappointing since the unit is so low and I sit up high. Also hoping the audio quality improves from the 10m that I heard it (going to add a ground loop isolator I think). Otherwise recommendable so far

vandal968

Bl79,
my unit looks identical to yours, but I got the 8core. I spliced the MOST adapter into the harness that came with the head unit since I didn't want to alter the factory wiring. The constant 12v and ground I took directly off that android harness, the SWITCHED 12v I am powering from the AMP power output from the head unit (it's a single bayonet fitting with a tag on it). I had to add one of the smaller included harnesses to get that connector IIRC. I think it's part of the harness that has all of the pre-amp outs thru RCA's. I noticed when tinkering that if the MOST box gets confused, it stays confused and doesn't come back until that switched 12v input is cycled off/on. If you've wired it so that it's always on (and that should be fine) it wouldn't allow it to reboot and clear itself if it gets confused. Mine has not gotten confused once since the install, but it got confused a few times DURING the install and needed to be power cycled to start working again.

cheers,
c

bl79

Thanks for the input Vandal. Yeah, that's exactly how I wired mine. Wired the MOST red "ACC" wire to the "Amp Con" blue wire which comes from the "RCA" harness that plugs into the back of the Android unit (one of the many harnesses included with the unit).

I've also confirmed the red "ACC" wire is getting switched 12V. At this point I'm pretty confident the MOST adapter is dead. Response from eBay seller has been predictable (asked for info/pics on how I wired it then after I tell him in great detail I get platitudes about reading the manual or whatever). I'm going to request a refund soon, we'll see how that goes...

At this point I'd highly recommend purchasing the MOST adapter through some sort of website with consumer protection (Amazon, ebay/paypal etc.)

vandal968

Bl79,
one last thing to double-check. I think that mine got confused at least once because the orange optical cables didn't go into the MOST box perfectly straight. I think I had to unclick, then reseat the connector perfectly straight then cycle power. The MOST box was definitely the most* fiddly part of the install. Also, my MOST box came with some kind of adapter pre-installed that had to be removed for the Porsche plug to insert properly.

cheers,
c

* See what I did there?

bl79

Ah, ok. I'll try power cycling it as you describe after re-inserting the fiber optic plug carefully.

I tried unplugging the RCA harness (and thereby switched 12V) whilst everything was on and powered in an attempt to powercycle as you had mentioned earlier but it didn't help any.

Oh, mine also came with the protection plug or whatever that had to be removed to get the car fiber optic plug in

DUTCH8

Thanks vandal.

For anyone in similar situation and because there were earlier some conflicting answers, let me update.

The MOST cables in my case (my car: Bose amp NO, Sat Nav YES), were indeed only for SatNav & Phone. The speakers (as well as Park Distance sound) were run independently of the MOST. So I was able to upgrade PCM 2.1 with a new HU without ordering any MOST adapters. The stock MOST cables are left unconnected and I am using SatNav & Phone from the new HU.