Alright guys I need some help. I’ve recently replaced the speakers in my blazer, but kept the factory head unit. Here is what I’ve done so far.

I cut the speaker wires near the back of the head unit. So the part that is connected to the factory harness now connects to a PAC device called SVEN. Like this (*** That is not the exact one I have. It is no longer listed ***). So the speakers run from the headunit to the SVEN. The SVEN outputs RCA’s to my amp. The Amp then sends the signal back to the factory wiring to connect the other side that I cut. I used the factory wiring to hookup my speakers. I’ll attach a diagram that will hopefully help visualize what I did.

Now here’s the problem. My headunit does not work anymore. I plugged everything back in and tried to turn it on but nothing. I know it has power because if I hit the eject button for the CD it will try to eject a CD (there was not one in it). Plus the little red light flashes on the face of the headunit. However, normally after disconnecting the battery I will have to enter a code in for the Theftlock system. This does not even show up. Thus, I need your help and wise teachings.

Also, It seems that every wire on my blazer is spoken for except two (Blue and Green) of which I have no idea what they go to. Maybe my tweeters? My amp needs a remote turn on lead...what should I use for this? The Dark Green 12v switched wire?

Thanks for your help!

 

unplug everything but the power to the radio and go from there

sounds like the head unit is busted

 

Turns out the system does not like it if you do not have all the little switches plugged in. And the radio does not work correctly if you do not have the lights module hooked up. So I plugged everything back in and it all worked correctly. Now I just have to see if that was also causing my battery to drain or if something else is doing that.

 

what the hell?

Oh...

sounds like something to do with the illumination.

the stock head units have the dimmer tied in with the rest of the dash.

Get an aftermarket head unit...

That's the best advice I can give.

 

I would run the blue to your amp and I'm betting the green is the dimmer if not maybe your head unit is fried

 

I got it working. Sorry I did not mention that. That was implied when I stated the system did not like it if you don't have the dash plugged in :-)

And I'm running the dark green switch wire (powered when the key is on) that is next to the constant orange as my amp turn on off wire. works very nicely.