any tips for 2002 envoy

I'm going to be installing an amp/sub in a 2002 GMC Envoy soon and was wondering if there are any types you guys have for wiring it up. I am going to be using a line out converter and keeping the stock radio. Is there any good LOCs out there you guys recommend? Also, this vehicle has two batteries in it. I'm guessing the best method would be to run the power from the battery under the hood to the amp and not from the battery under the seat. Any other suggestions or comments for this vehicle would be greatly appreciated! BTW, I'm putting in an 800 watt RMS amp.

I would hope that you are wrong when you say that there is a battery under the seat. If you are refering to the item under the rear seat behind the driver's seat, this isn't a battery. It is the BCM and rear fuse box. Installing a battery inside a vehicle isn't safe. Unless the battery is sealed, it will vent acidic fumes. Run the amp's power wire off the underhood battery and make sure that you install a fuse inline within 18 inches of the battery.sparky

I have a 03 TB and the BCM and fuse box that is underneath the seat is where I ran my blue wire for the remote to turn on the amp and power cable I ran through the firewall to the battery.