Ok mate! Let me try my best to explain my situation, and then what you could try..
So, my left speaker stopped working, but my setup was different, I had two external amps in the boot - one powering the front left/right speakers and one powering a sub.
At first, I thought the left speaker had blown, so I bought new speakers. When I fitted the new speakers, I proved they both worked using the external amp, fitted them and was very disappointed to discover the front left one still didn't work, I switched them round.. just to be sure - no luck. Then, I thought the amp in the boot had stopped working, so removed that, wired up the speakers back to the original set up - It worked, briefly, but then the speaker stopped again - weird.
So, at this stage I was pretty much in the same boat as you.. a Pioneer headunit powering two aftermarket speakers using the original speaker cables. The only thing that might be different is the ISO adaptor and that it's a double din. Unfortunately, I am not sure exactly what is standard on a DC5, but my headunit is connected in with an adaptor loom that looks a bit like this - I've borrowed this from the internet:
I concluded it next must be the headunit, which it seems is where you're thinking is... I found a new ISO adaptor, connected that to the original car cabling harness/loom and fitted a different Kenwood single din headunit... It gave exactly the same issue - left speaker not working.
So at this stage - it wasn't the speakers, it wasn't the headunit - it wasn't the ISO adaptor harnesses.. I even did voltage testing down all the cables and all seemed fine.
...................................................................... cue frustration. :xaiweb4:
The next thing I tried was starting to change the connections in my wiring harness (referring back to the image above). On this harness, all of the wires are labelled for front left/right positive/negative etc: FL+ FL- FL+ FR- and I was able to connect them up to the DC5 harness - which aren't labelled but are coloured as below:
DC5 OEM Wiring Diagram:
Black - Ground
Red - Dimmer
White/Red - Constant 12V
Red/Black - Illumination
Yellow/Red - Switched 12V
Green - Front Left speaker (-)
Green/Black - Front left speaker (+)
Grey/Red - Front right speaker (-)
Green/Yellow - Front right speaker (+)
Blue/Black - Back left speaker (-)
Blue/White - Back left speaker (+)
Blue/Yellow - Back right speaker (-)
Pink - Back right speaker (+)
..from memory there should also be: Blue - remote
So, I switched the Front left +/- respectively with the Front right +/- and I got the same issue - the left speaker still didn't work, and the right speaker was fine. What I had proven here is that the headunit Left/Right outputs were working 100% as well as the harness as it was always capable of powering the front right speaker.. always with the left speaker not working.
At this stage I concluded it has to be the OEM speaker wiring that runs from behind the door card from the speaker to the harness adaptor that's gone wrong. Even this was hard to believe as occasionally I could get the speaker to make some noises.. I also discovered that not even having a speaker attached could cause the headunit to do slightly odd things, if the harness was attached to the front left cabling...
My solution
Disconnect the DC5's OEM wiring to the front left speaker and run a new wire from headunit harness, behind the dash, through the door gromit and to the speaker..
So, I recommend you try the following:
- Be safe and disconnect your battery each time before fiddling around with all the cables..
- Check if your harness will allow you to switch L/R outputs - if so, switch them and check results!
- Check what your new headunit ISO/harness adaptor is like - also might allow you to switch L/R outputs. (although if you haven't opened it you may wish to return this if it's not the headunit)
- Does the right speaker always work? Does the left speaker always remain not working?
- If the harnesses are not suitable - consider working out what is the Left speaker wire on the harness by tracing the colours, as mentioned above, and splicing directly into the harness, so a speaker is attached to the headunit bypassing any of the DC5 OEM wiring. If left and right work - you've got the same issue as me.
If you're still with me and all that makes sense - great. Otherwise, any questions just ask.
