I have a 1999 tahoe. how do I know if it has the wiring already installed to add a second battery? It already has the tray.

There is a long wire that runs from the battery across the front of the truck and ends at the underhood fuse panel what is this for? power for the fuse box or aux wiring?

http://pic6.picturetrail.com/VOL176/1467695/3086432/61166547.jpg

Our 2500 @ work has dual batt. It wont be that hard to wire another batt. Just make sure you wire it in parallel. If you dont get get me, feell free to ask.

What is the benefit of having two batteries? I have a 99 Tahoe and am thinking about adding a 2nd battery. Thanks!

I ended up going with an isolator

What is the benefit of having two batteries? I have a 99 Tahoe and am thinking about adding a 2nd battery. Thanks!

You get more crankin amps, you can run your stereo longer w/o the engine runnin. More juice basicaly

Will a dual battery system effect the alternator?

Nope cuz your car still goin to pull the same amount off load as if you only had one batt. Just make sure you hook it in parallel and NOT in series.