rca converter

I am installing a jl 500/1  and 2 12" subs in my all stock 2000 maxima w/ bose

here`s my problem: I spliced a pac 35 into the + white wire and -black wire  ( following mitchell`s schematic)          just before the bose sub but after the bose amp.

after finishishing the install I have no sound in the new sub box. I have 4 volts on all 4 wires at the pac converter

however I am not getting anything out of the rca outputs ( should  have a v+ reading? )after going over the obvious connections elsewhere I am now stumped !!!!

Thank you for the chart as I would have never of guessed that the  cigarette pack looking devise under the speaker  could possibly be an amp! 

Is it that the signal is too low on  the wires I chose?  I will try  to wire this converter after the sub amp.

If you are using a Pac SNI-35 it definitely needs to go after the sub amp.

Thanks for the help. But I still could not get a signal to my amp even after the bose sub amp.

So , I went hillbilly and cut the rca cable and wired it to the low output of the first bose amp and presto, it actually sounds nice!!!!!!