Factory Option Amplifier Subwoofer

[ALIKA T3]

[ALIKA T3]

[jimf909]

https://www.thesamba.com/vw/forum/viewtopic.php?p=10007107#10007107

[jlrftype7]

[syncrodoka]

[jimf909]

Dang, now I remember your photo of the plastic box. Oh well.
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- Jim

[RawUmber]

If you're looking for the pinout of the red "Aktiv" connector, this page might be helpful:
http://a2resource.com/electrical/radios.html

Cross-referencing the above page, it appears that your red Aktiv connector has these receptacles populated:

[ALIKA T3]

[BrownEye02]

Thanks everyone for your research on this!
I finally got around to playing with my factory "sub" tonight. It's just a twist wire test so bare with me.
My adapter had a blue and white wire that was not used but was in the wrong position for the factory white and blue wire. I simply unpinned it and moved it in line with the blue and white wire. I then wired the adapter blue wire to my stereos remote/trigger wire.

On stereo power up I heard the usual amp pop as if the sub amp was turning on so I knew I was in the right direction.
I then wired the AKTIV connectors green wire into the + of an RCA wire and the brown and yellow to the ground. I was able to get the speaker moving but even bumping up my stereos pre-amp gain it was barely doing anything. I was only able to get the sub to visible wiggle with a tone generator and even with that it was barely moving.

I REALLY don't want to take off that interior panel covering everything due to how big of a pain it is so I've just been going off of ALIKA T3's photos of the sub amps wiring.

Now my sub speaker is torn like all the ones there are pictures of so this might be a factor.
My other thought is maybe the factory blue and white trigger wire is more then that and needs a bit more juice then what the new stereo can provide. My stereo provides 12v on that wire but maybe it's an amperage limit. Though I have my doubts with this one as I'd assume my stereo fuse would blow if the factory amp was using the trigger wire as a power source per say. I will still do a direct to battery connection test just to confirm this isn't my issue.

I did try to jump the amps speaker green wire and brown/yellow wires to the stereos front + and - but the stereo would cut out when doing this. I could have caused a short with how bad my tests were but I don't think that was the case here. I something else was in play. My true concern is that the factory stereo would act as a form of amp and then the sub amp would take care of the rest. Something a modern day pre-amp output won't do. This is why I was trying to connect one of the stereo speaker outs to tap into its amp to see if that would help.
Either way more to come as I play with this.

[Crankey]

[BrownEye02]

Got to play with this a bit more today. I decided to solder in the RCA cables as this will just make future tests easier to do. I'd highly recommend using using an RCA connector where the - and + are separate unlike the one I used where the - is the shielding. It will just make your wiring cleaner and less of a hassle to deal with. But here is the end result. I also kept the factory connector.

In my initial testing I was only able to test either the left or right channels. I was hoping that having both the left and right would possibly resolve the weak sub issue being its a dual coil sub but sadly that wasn't the case. The video below shows the sub working. This is using a tone sweep video so it looks more impressive then it actually is. This is also with the volume pretty high and the pre-amp gain maxed out on the stereo. I.E. - the sub should be REALLY getting worked and its not.
https://photos.app.goo.gl/9nz32rSEvNdTd5cw8

I got a chance to dig into the sub a bit too. I wanted to get some measurements to see if I could find a suitable replacement speaker. If anyone else digs into theirs, word of warning! There are washers not only on the front side but also on the back side of the speaker screws. I'm not sure if knowing this before hand will help since its a tight squeeze to get your hands in there. But, maybe I can save you a good 15 minutes of trying to recover the washers from behind the panel.

I believe the part number to be 3637621038 as this number matches up with the photos from earlier in the thread. Sadly googling this turns up nothing. My hope was to find what wattage this speaker is.

The next things I'd like to try is finding a way to amplify the signal going to the sub as well as possibly replace the speaker. For testing I'd even be ok with a single coil speaker just to see if investing further money into this is worth it or is a loss cause. I know I'm not going to get standalone after market sub quality out of this but if I can make it audible and its even a minor improvement vs without, I'd be happy.

One thing that I thought of but couldn't find any thing is where a fuse might be for this. Since our Van's have the possibility for extra fuses on the top of the fuse block. I though I'd find something there but I came up empty. My van has the fuses for the automatic locks and instrument lighting. My only other guess would be that the sub amp is just using the same fuse as the radio system but I feel that would be a bit odd. On top of that, I'd expect them to use a slightly higher amp fuse if this were the case and its not.

[ALIKA T3]

I'm a bit lost with the work as this is not my fiel but the sub was powered off the radio, so prolly the same fuse, no?
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget

[BrownEye02]

My assumption is sub is triggered off the radio but not powered off of it. Like a relay.
Looking at your original photos the "larger" red and yellow wires or brown and red if looking at the connector going to the entire sub box, I'm assuming are the dedicated power and ground lines for the amp. That's what I'm also assuming would have its own fuse.

[ALIKA T3]

Revisiting my own pics and memory, it all goes to the radio deck, split between 2 connectors: the red one, and the white one for power, which the red is double ganged off the radio power.

I stripped the entire hardness when I took it out, there's no wires going to the fuse panel directly.
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget

[BrownEye02]

Ahhhhh, good to know!!! Thanks for the follow up on this!

[ALIKA T3]

Anytime
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget

[Red Ryder]

Probably been mentioned already, but can you really get much bass out of a speaker that small? Most “modern” subs are 8” and larger.
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“Most everyone’s mad here. You may have noticed I am not quite all there myself.” — Cheshire Cat, Adventures of Alice in Wonderland

“Scarlett” — 1990 Vanagon Carat Wolfsburg Edition
Tornado Red

[ALIKA T3]