Output from DSP w/RCA Center Pin Input Only

I've got a Zapco Z8 IV and am having problems after the install.I send a signal into channels 1 and 2 of the inputs and get no output from any channel UNLESS I pull the RCA out to where only the positive is touching.Bypassing the DSP and sending the signal straight into the amps works fine but the second I send a signal into the processor nothing but problems! I did have a mishap finalizing the wiring where the tweeter wire was grounding and sent one of the amps into protect.This actually damaged the stock HU.The DSP never went into protect of any kind though nor did the other amp(2 amps total in the system).The stock HU was replaced and works fine now along with the 2 amps but this DSP is giving me nothing but problems. FWIW I'm sending the stock low level signal into the DSP's front 2 input channels(RCA's).I read 3.6 volts with a -5db sinewave on full tilt coming from the stock HU.I also tried using my old Sony HU and sent the pre amps from it and still NADA out of the DSP outputs. Anybody got any other thoughts on what I should try? Or does anybody have experience with this processor?Rumors of Bob but never Bob......So what is it you tell people you do these days Bob?

What is the year, make, and model of vehicle? If you're not using an LOC, which wires are you using for the low level output signal from the stock head unit? If you are using a line output converter, which one are you using and how exactly is it wired? Have you confirmed you have power to the DSP and that it is turning on? the12volt • Support the12volt.com

Got DSP up and running now.Its a 2011 GMC Terrain.The vehicle has a stock amplifier.I unplugged the low level harness from stock amp and am using the 2 front channels for a signal.I researched tons and know that the signal is full range.Measured 3.2v at -5db 40hz tone and 6.3v at 0db 40hz tone.Does that signal voltage merit using the high level inputs of the DSP or is it ok going into the low level RCA inputs? I am not using a LOC,just the stock low level outputs.Rumors of Bob but never Bob......So what is it you tell people you do these days Bob?

If it's working and sounds right, then there is no need to add a line output converter. What did you do to fix your problem? the12volt • Support the12volt.com

Turns out the DSP remote that I mounted to the dash was set to SDPIF(optical).Source needs to be set on "Main" for the RCA inputs.All the stress and testing,etc and all I had to do was go up front and hit a button!Rumors of Bob but never Bob......So what is it you tell people you do these days Bob?