This is a difficult question to Google for, since I don't know which component is causing the failure.
I have a 2010 WRX with the factory navigation. It looks like
this. I just bought a
Sound Ordnance B-8PT subwoofer to put under the seat. When I got it all wired up, the amp would not turn on.
I busted out my multi-meter. It shows power on the battery wire all the time and power on the remote turn-on wire when the deck is on. Exactly as it should be. I can't figure out why the thing won't turn on. To test it out, I took a bit of wire and bridged the battery wire to the remote turn-on terminal. Sure enough, the amp fired up and the speaker started working. That tells me the problem is with the remote turn-on wire.
The only thing I can think of is that the deck isn't pushing enough amperage through the remote wire. I don't know exactly how to read my multi-meter, but the Battery wire is pushing a lot more current than the remote one.
Does my hypothesis seem reasonable? Does anyone know if this is a common issue? I could try tapping the ACC wire off my stereo, or even pull from the cigarette lighter or something, but I'd really like to understand what's going wrong here before I start hacking something up.