Im sure someone can point me to the right way to get this thing going? I just hooked up all my grounds, e break, speed sensor and had to power up main power lead from new head unit, i thought new harness from sound gate would do this but when i tryed i got nothing until i tapped into acc. power from under dash to head unit power wire. well with that being said i powered up and i have no door subs just the mids, played with the unit and still have no bass, i did however move the black wire/ pin in the harness from one side to the other... soundgate says if you have a 99 or newer to do this , well i have a 98 thought i would give it a try, still no bass, I hope this is not how the new head unit sounds on the existing sound system,, oh,, one more thing, the new soundgate interface has just 2 plugs but existing wiring harness from sound system has 3 what the,,, guess its not needed??? please help if you can...just would like to add that im modding like crazy right now the bat. is not up to full charge and cant start the vert beacuse alt. bracket is out getting cromed, but not really sure the car need to be running at all for just bass,,, well like i said any help with this would be welcome

 

i just installed the soundgate GMCRV1 in my car, I got everything working on the 1st try. As for the constant power wire the soundgate units "YELLOW" wire is just for this. I used the accssory harness in the passenger floorboard for my ground and "Switched 12v+ power. There is a **** on the interface that controls the gain of the door subwoofers.....you did turn this UP right?

the interface works, sounds liek u got some wires crossed somewhere.

 

I just did the same and I had to move the ground wire across the harness to get some bass (mine's a 99, btw). I'm still not 100% impressed with the bass, but tweaking around with the settings and EQ gets it pretty decent. As for the 3rd harness, I wonder if your car is pre-wired for a CD changer?