Where I can buy the wires for kenwood powered subwoofer ksc-wa100? please help me I search and I don't find that.

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 .

https://www.manualslib.com/manual/287091/Kenwood-Ksc-Wa100.html?page=5#manual

Please see this page:
KENWOOD KSC WA82RC Service Manual free download schematics eeprom...

You may need to wait a few minutes for the "Get Manual" link to appear below the preview picture.

if you are looking to just run the power solely through other speakers this will prolly not work you will still need to have power going to the amplifier.

Hello mikealtre,

Hopefully there's enough of the wires left to see their colors.

Here's a link to the manual. Other than the speaker level inputs, there's only 3 wires you need to be concerned with. Yellow is main power, black is ground, and blue is remote.

Hope this helps.

Never Use That Thing Again

If it is one sub with one amp, one remote needs to be hooked up. Not familar with your exact set up, but should stay constant for all. The remote signals the amp to turn on power when the deck is turned on thats it.

1 wire might be a remote turn on 4 the lost amp. connect a light tester to the ground wire turn on and off the pre amp and see if the light goes on and off 1 might also be a floating ground wire .

Here is a picture to help you out.

You should run a new power wire to the battery or fuse box from the Sub. For safety there should be a fuse on the cable at the battery or fusebox end.