old dog

another repost of dual battery install !!!!!!!!! Dual Battery Install Instructions for a Chevy [/align] [hr] Please make this a Sticky Forum Mod..

This is compliments of B&B.
Here is a complete install instructions for all of you trying to hook up dual batteries. Good Luck.....

The battery tray is a easy to add, you just use the factory aux battery tray from GM and it will bolt into the stock location just like GM intented.. The tray is mounted on the pass side inner fender between the coolant tank and the firewall. You will need to remove the upper curved fender brace between the fender and the firewall to provide the clearance for the battery but it won't affect the structural integrity of the fender. Depending on the physical size of the battery you going to mount in the tray, you may need to trim the tab off the firewall where the fender brace was mounted that you just removed. A quick zip with an air saw or even tin snips will remove it easily. Use a file and a little touch up paint on the cut edge to dress it up a bit.

The part numbers you need to get from the dealer are:
Support: 15705102
Screw: 11509853
Clamp: 356668



The easiest way to wire duel batteries to the 99-up Silverados is to use batteries that have top and side terminals both. By having top and side terminals both, you can just leave your stock cables the way they are and use the top posts for all your additional connections. I like to use a set of top post terminals like these here: http://www.sonicelectronix.com/item_...y+Terminal.htm I just provided the link so you'd know what to look for since you can buy them at a local store like NAPA or AutoZone or most any stereo shop. I also like the fact that these terminals are gold plated so they last a lot longer as far as corrosion goes.These style terminals make this a super easy job because if you look closely at the pic, they have ports in them that you just strip the insulation off the cable and insert it into the port in the terminal.They have an Allen set screw in them to tighten the cable. That way you don't need to crimp any cables. I do recommend adding a little solder to the stripped end of the cable though so the Allen screw doesn't crush the cable and will add additional contact surface. Just buy enough cable to reach from one battery to the other how ever you want to route them around the engine compartment and simply connect the positive on one battery to the positive of the other battery terminal. Do the same thing on the negative side too.

Three other things that I would recommend doing at this time:

1) Upgrade the charging wire on the back of the alternator to a 4 gage cable as this is a weak link on the GM trucks. Leave the stock one in place but add a second one from the charging stud (where the original wire is on the alternator) directly to the positive on either battery (driver side would be closer).

2) Add an extra ground cable from the aux battery to the frame, and one from the frame to the engine.

For these 3 cables you can just buy a replacement universal battery cable with an eye on one end. Then you can just cut the other end off (doesn't even matter what kind of end is on this side as your cutting it off anyway) and insert it into your gold plated terminal.

Make sure both the power and ground cables for the plow are connected directly to a battery. Do not connect them to the factory pos junction block near the power steering pump or connect the ground anywhere but the battery. This will allow a clean voltage path directly from the batteries to the plow where it's need the most.

That's why these gold plated "port" style battery terminals are so handy, since they're easy to add extra cables to and they still look clean and neat with good conductivity.

You want to use 2 gage cable for all these wiring upgrades (except the new alternator wire, use 4 gage like mentioned)

Adding the duel batteries connected directly togethter and upgrading the stock charging wire and ground cables will allow the system to operate at peak efficiency and allow the alternator to provide all the amperage it can to keep the batteries charged.[/align] __________________
streetfrog@comcast.net

CharlyG

So, I have a 98 C2500 with an extra battery and no code for it. Maybe it was an out of state truck used for plowing? It didn't have the camper special code so I assume it was added. Why would I still want it in place? We have a TT that we don't drycamp with, always at a RV Park, so I am not sure what I am gaining by hauling around this extra battery.


Thanks!

old dog

well if you do not have a need for extra power ,trailer breakaway ,plow ,power inverter ,winch .i guess it would not be necessary ! could have been added, or they plowed ,had extra equipment they had to maintain .

CharlyG

Thanks! I will wait a bit and mull it over.