Running straight power from the battery suggests there's another option, as for instance running mains power...
How could having two ground wires work, please?
Take a look at this manual diagram. https://www.manualslib.com/manual/359815/Kenwood-Ksc-Sw10.html?page=5#manual
Given the above is not your model, at least it shows the 10 pin. Ironically, below I offer a diagram of your model. The irony comes in the fact that the diagram appears labeled in Japanese But if you compare the two diagrams, maybe something will make sense from the one with the English labels. Otherwise, you might fire off a query to Kenwood customer support. https://www.manualscenter.com/manuals/kenwood/kscsw900-owner-manual.html
Here is a 10 pin harness compatible with the subwoofer. Kenwood Subwoofer Amp KSC Wa100 Wa80 Sw10 10 Pin Harness for sale online ' eBay
I don't have any information on how to power supply a kCSWA900 Kenwood subwoofer. However, I can tell you that the Kenwood KSC-SW10 compact powered subwoofer has a built-in amplifier with a 38 watts RMS power and a wired remote for control over volume level, variable low-pass crossover (50-120 Hz), and selectable phase control (0°, 180°) . The subwoofer comes with a power/ground wiring harness and preamp (RCA) and speaker-level inputs .
The manual says a code 10 is Electrical or mechanical. The say the solution is to turn the ignition on and off, or switch to a different source, then back to cd player.
Chek the power supply section. It seems power is available up to LED portion and further it is open circuit. Possible there is a power regulator after LED Portion that is not working.
After researching, it appears that there is no direct evidence suggesting that the Alpine TDM 7543 stereo unit has the ability to switch from green to red lighting. This is an older unit and specific information can be challenging to find. Your best option to get a definitive answer may be to directly contact Alpine's customer service or refer to the original instruction manual.
