Boss powered sub not working

Make sure you did not reverse polarity when you attached to the speaker, if you did you grounded the outputs through the BOSS! Are you working of the Toyota electronics schematic?
Do you have the volume on the BOSS turned up?
Can you input some external audio into the BOSS to verify that it indeed works.
Are you sure there are low frequency's on the speakers you tapped into?
On my Gen II, the amp has crossovers built in, I used the full sound back door feeds to drive my BOSS.
I would advise going to the Toyota Information Services, website pay the $15 bucks and download the PDF files for your car. You have 48 hours access, it's easy, and is perfect for all Prius occasions, well just like this one!

 

OK, do you still have audio coming out of the speakers you tapped into?
There is a input level adjust on the BOSS, and mine had a remote volume control, does yours?
If so they have to be turned up to allow audio into, and control volume of the amp.
The fact that the green light comes on, I also think your sense line connect is OK.
Worst case, the BOSS itself is bad!

 

I just hooked up a Boss800 and I am having the same issues. Green light on. No sound. All speakers still work. I hooked up to the speaker wires of the existing OEM amplifier under the passenger side seat. I will check again that I did not cross the polarity of any of the wires. I used the supplied wire harness and connected with the High Level Inputs (no RCA Cables). Please keep us updated. I will do the same.



Updated 3-14-13. I have a question. Did I need to use specific sized speaker wire? I currently have 14 gauge speaker wire connected to the very small OEM amplifier wire then back to the very small wires on the Boss wire harness. Is this O.K.?

 

Update: 3-15-2013.
I found that if I only inserted the Boss included wire harness about 80% of the way into (before it clicks) the High Level Input socket, the subwoofer would work. I am going to return it and get another just like it. Hopefully, the next one will not have the same issue. It took me awhile to jingle it just right to get it to work.

 

Yes, you are not relying on power but signal. There is a resistive pad built into the input to reduce the speaker level signal to a much lower usable one. You just need to get the signal to the BOSS!

 

Update 3-28-13. I got a new Boss800 it did the same thing when I tried using the high input adapter. I purchased a Boss converter off Ebay for $9.78 that connects the speaker wires high input to the low input RCA type connections. Now the subwoofer works perfectly. If I had used the correct sized speaker wire like you suggested I probably would not have had to purchase the converter. I didn't check back after I thought the unit was defective. Thanks.

 

I am glad you got it working, but you got me stumped as to why the Hi Level in did not work on 2 amps! The adapter you bought was a smart move, it got you the results you want. Just remember not to set the input level adjust too high, if you do it will activate a protection shut down circuit and mute the BOSS. Worst case, it will blow up the BOSS amp! You can turn the output knob all the way up, but watch that input!
Enjoy it!