Fender audio subwoofer not working

I just picked up a 2016 GTI with Fender audio in it a couple weeks ago. The PO had an aftermarket amp and sub in it, all of the wiring from it appears to still be in place. I can't afford to plug in another aftermarket amp/sub right now though.

The Fender sub is still in place and plugged in but I'm getting no output from it. I've made sure that it's turned up on the radio setup screen. All of the other speakers work without issue.

I haven't had a chance to pull out the HU yet to see what the situation is behind it. Is there anything I should check in coding with OBDEleven as well?

Thanks in advance for any help/suggestions.

If they had an aftermarket amp in there...they would've had to use a converter or tie into the speaker signal somewhere.
Look behind the radio and/or near the Fender amp under the seat to make sure they didn't hack the wiring up

Is the fender sub plugged in? Maybe they used the stock wiring to power a different subwoofer and had tapped into it with the amplifier. Weird, sounds like they left the amp and wiring but not the sub they were using. Fender would NOT be used with an aftermarket sub, it can’t handle the OEM power. Is the amp getting power?

I'm hoping to get a look at it this weekend. I'll report back with findings. Thanks.

If it's possible to bring it to where you bought it, then I'd let them deal with it. Hopefully it's just been coded out of the setup.

I went through all of the points of interest this morning. The harness behind the infotainment unit has a white wire that appears to have been taped off. The black tape isn't the same as the VW stuff.


The amp looks ok under the seat. I unplugged and replugged it as well.


Here's the trunk with everything coming into it. Control and speaker lines first, then the amp power/ground, then the cable/fuse that I pulled off of my battery. I unplugged/replugged the sub while I was back there.




Finally, the engine bay, a few weird things here.

The other end of the giant power cable

Spliced into a fuse...

umm...no idea what this is... note that the 5A fuse to the left is blown as well

At this point I think I'm going to have to bite the bullet and go to a stereo shop for some help...and probably get talked into a sub/amp combo.

edit ------
Well, none of my image links came in...must be because I'm a junior member still. I switched them to URLs for now.

Just my 2 cents but if all you want is to have the factory stereo working ( including sub ) all you have to do is find out where he spliced the wires and reconnect them. As long as you have all the components, i.e. sub, amp and wiring, you just need to do some wire tracing to find where he cut into and then reconnect those wires. You shouldn't have to take it to a shop just to find that out.

Also, it looks like he was powering an amp and something else(loc, dsp?) I don't know why he didn't run both power wires to the side of the fuse block instead of tapping one into an actual fuse?? Anyway, good luck and keep us posted!

Good gawd what a hack job.

Adurm said:

Good gawd what a hack job.

Click to expand...

And it was done by a “pro shop” that’s been in business for 20+ years.

Finally got back to this. They had spliced into the rear speaker wires under the driver door sill. After putting the four original wires back together I've got rear speakers and a sub again.

Glad you got it fixed. Sometimes an aftermarket job seems like a bigger mess than it is because of all the things they added. You just need to find where they tapped in for a signal.