Fender Audio Wiring Harness Schematic? - 2019 VW GTI MK7.5

[01LSi]

No ill tone taken. I was joking how you posted a couple days ago to get a wiring diagram then pow! zen tv interface. I can confirm on the mib 2 non nav, non fender speaker wire outs are not flat nor do the frequencies increase linearly. I just hooked up the audiocontrol dm810 that has input and output rta. The 400 to 1k range was spiked up while the sub for the most part was low. My max volume is 15/30 with the bass turned down 1 to avoid clipping 35 and 45 hz. I was hoping the rear speakers off the mib would be usable but the dm810 causes an audible delay to do its job. Like .25 or .5sec.

I was hoping to find a cheap most to toslink wire and code mine to use the most for better s/n ratio. Im sure the zen is a great piece of equipment, but I'm already too deep to jump into that. Saving my strength for an s3 or a3 is38. Then 3 way active up front. I think there's a spot for a 3.5 in the door.

Last car had a JL Fix (and TWK, later Helix) with optical out ... never sounded right to me even though it was a "flat" output. Thank you for all that detailed info! I haven't really caught anyone explicitly saying they tested if the signal was flat. Let me know if you ever figure out something out, the whole MOST system is new and foreign to me.

I'd say keep holding out for the S3 the only reason I leaned towards the GTI instead of S3 was because at the time I wanted to be able to eek out the smallest (and still fun/practical) car possible so I wouldn't have to pass so many potential parking spots. Not in that situation anymore, but I was going crazy circling blocks for 30 minutes at a time mumbling "a GTI would fit in there". Still a great car but if I knew my circumstances were going to shift for the better I would have gone with the S3.

 

[Adurm]

I wanted a manual that i could fit in. Not many for us 6 plus ft. Too old for a wrx or sti. Now becoming more reasonable to have an automatic in case the wife needs to drive it. There's an 8k difference between 2015 a3 2.0 quattro vs s3. It's a dilemma.

If i remember, maybe i can get a screen shot of my output rta eq curve to give an idea of what it's auto calculating.

 

[Adurm]

So i decided to reevaluate the mib II front speaker level outputs in regards to frequency response, voltage, clipping etc. Trying to find the flattest rta curve at whatever volume gives up to 8v signal. It's going to take some time. Current findings with the car running, ac off, using a very cheap scope, i find no clipping or noticeable distortion across any of the 30 bands plus a few extra frequencies at 30/30 volume. Quick voltage check was at 9.1v I did see on the audiocontrol dm810 input rta where the stock bass, mid and high sliders impact. Bass is centered at 40 to 50 hz, mids 800 to 1khz, highs 12.5 to 16khz. I have not tested for clipping when pushing those up yet. This is done with 16/44.1 wav files at -.002 dB.

My intention is to eval every frequency at every volume. It's going to be fun running from the stereo to the boot 900 plus times. Should probably pull my signal wire from the back up to the front seat. I'll make a post when it's done.

 

[Adurm]

Quick update: moving the stock bass, mid and treble slider up one click is equivalent to that same band but at 1 click higher on volume. As in level 16 volume, bass plus 1 equals the same bass you'd get at volume 17 while everything else is the same. I could not demonstrate clipping at max volume with the sliders maxed even at the strongest frequency voltages. Ultimately settled at volume 16/30 with trebble plus 1 for the flattest response under 8v. Lots of tuning to come. What have i done to myself? Remember wiring stuff up way back and hoping for the best. This scientific business is frustrating.

 

[01LSi]

Quick update: moving the stock bass, mid and treble slider up one click is equivalent to that same band but at 1 click higher on volume. As in level 16 volume, bass plus 1 equals the same bass you'd get at volume 17 while everything else is the same. I could not demonstrate clipping at max volume with the sliders maxed even at the strongest frequency voltages. Ultimately settled at volume 16/30 with trebble plus 1 for the flattest response under 8v. Lots of tuning to come. What have i done to myself? Remember wiring stuff up way back and hoping for the best. This scientific business is frustrating.

Yea I hate the whole OEM integration thing so much ... even back then you'd at least more likely know what you're getting by swapping the head unit. It's interesting for sure but I don't want to be the pioneer of the details. I'd rather someone tell me exactly what's needed and I learn in retrospect.

I've settled on de-pinning the factory harness and connecting with OEM terminals. Was going to be too much to solder the male harness I got from Mouser. Got color coded 16ga tinned copper all wired, twisted, terminated with the male spades from mouser so they click in, and bundled up. With heatshrink on the connection it's not going anywhere and I can click the old pins back into the OEM harness so fully reversible.

So with the basic car audio system you're saying the signal is flat and undistorted all the way through huh? If so thats a great outcome.

 

[Adurm]

You're wiring looks very pro. I've never been that keen with wire management.

Ya the base system gives a fairly flat response at 15 to 16. There are a few dips here and there but i didn't have to adjust my dsp out eq much to get there. Of course tuning the speakers to the environment with a mic and ears is a whole different story. I don't think i had to go more than +/- 1 dB anywhere. I did run into an issue where my better volt meter wouldn't read 4khz and higher as anything over 5v. My $5 meter would but i think it has a higher margin of error. The cheapo one seems about 5 to 10% lower reading than the other which is not a Fluke made device.

 

[tshrey]

Any tips on getting the pins out of the fender harness? I thought I could get away with making my own tool using a paperclip and just jamming it into the release holes but it doesn't work.

 

[George Ab]

Any tips on getting the pins out of the fender harness? I thought I could get away with making my own tool using a paperclip and just jamming it into the release holes but it doesn't work.

I went in spouse's sewing kit and used sewing needles. Not ideal, but it worked.

 

[nonoabby123]

Awesome cable wiring job!

I tried something similar when I ran new wires from my amp/dsp to to my new speakers. Using open pin holes in the original connector.

Pulled oem pins and wires from a used harness and spliced to 16 awg. I used small staples to release those pins.

 

[kyle_h]

I bought the male housing for the fender amplifier plug and a bunch of TE terminals

View attachment 168145

Where did you buy this???

 

[DV52]

I guess i don't understand the requirements of most interface. Just send the light through the cable already. My dsp gladly takes toslink.

@Adurm: That's correct - to a degree! However, the fiber-cable topology for MOST 150 is a ring like this:

Now - the "TV tuner" in the picture is only sold in the Japanese market (I have no idea why a TV is installed in a car) and the "Digital sound package" is the RoW model equivalent to your Yankee model Fender systems.

However, notice that MOST relies on a ring architecture - so for successful communications to happen, the optical message must be sent to the receiving module AND it must be sent back to the initiating module by the receiver. The ring topology provides an additional degree of integrity in the communications infrastructure - which is further enhanced via a separate "ring circuit break diagnostics" facility which is a copper-wire system that uses a hub-and-spoke topology, but I digress!

So, that's why there are 2 x optical cables in a MOST pair - and they use FAKRA connectors

Don

 

[FSTSNAL]

I have one question. What order are the wires in the front door woofer connector? In after market adapters it is + + - - with the 2 + and the 2 - connected. The wiring diagram shows it as - + - + but they are 1 3 2 4 would I expect them to be in the order 1 2 3 4 so - - + +

I ordered an iDatalink Maestro ar to replace the amp and connect to Audison ap amps. Just trying to be sure I have everything I need before tearing into it. If this route works I will post all of the info. Took a fair bit of research before I settled on this route.

 

[FSTSNAL]

From your analysis which pins power which speakers? Looking at the wiring diagram in the factory manual it lists it as a 38 pin connector and some of my wires are missing n the 30s so in that second harness in the connector. How is it numbered.

I also bought an amp replacement module from iDatalink I am trying to get to work. Looks like they have a file in beta for facelift. However their guide shows different speakers connected in spots than my analysis unless I am reading the wiring diagram incorrectly.