Discovery 2 Speaker and wiring mysteries

[fowlerjk04]

This is a combination of issues, I think. At least a combination of symptoms.

With the 2000 D2, I have an aftermarket head unit (bought that way) and it appears the subwoofer in the rear door is missing. I have audio from the front speakers without any problem. However, the rear speakers only produce the hum we all know that is tied to a ground fault (you know, the one that changes with engine RPM). Sometimes it's there, sometimes it isn't. Regardless of hum, the rear speakers never produce audio output from the head unit.

I have tinkered with all audio settings. No change.

I assume there's a loose connection between the head unit and rear speakers. Sounds like it was never connected at all and the wires are hitting something every now and again that allow that hum to happen.

Where to start tearing this thing apart and troubleshooting? I am very nervous about pulling panels. Brittle plastic scares me. I'd love to pull it all and do a complete rewire with a stock D2 head unit or one that will keep bluetooth/carplay capabilities without looking so out of place in the dash.

 

[kris812]

The amplifier above the passenger right kick panel underneath the dash should be a starting point.. To be installed correctly they would have by passed the factory AMP. Odds are wires were never put in right or not everything was bypassed and you're hearing the factory amplifier THD total harmonic distortion without its grounds connected.

 

[fowlerjk04]

The amplifier above the passenger right kick panel underneath the dash should be a starting point.. To be installed correctly they would have by passed the factory AMP. Odds are wires were never put in right or not everything was bypassed and you're hearing the factory amplifier THD total harmonic distortion without its grounds connected.

I pulled the kick panel and didn't see anything, so I assume there's no amp there. It's too crowded. The factory amplifier under my driver's seat looks to be connected OK. This is a high-line system with the HK speakers everywhere. I reseated the amplifier connector just to see if that would have any effect. Everything turned off when I disconnected it and came back when I reseated it, but no difference in speaker audio. Pulled the Kenwood head unit and swapped around the connectors. Front/Rear/SW available in the back and the only two connected were Front, which I assume goes to the amp for distribution to ALL the speakers. Swapping them around had no effect. While I was doing this with the engine off I noticed the rear speakers came alive with static but no audio.

What should I investigate next? I wonder if the amp itself has gone bad? It appears to be powering those rear door speakers but no audio from the head unit.