Oem Dual Battery (gmt800)

OmarR · February 13, 2009

I pieced together the OEM dual battery kit from the dealer.

Here is a pic of the main positive cable:

Obviously one end connects to the battery, but then I have 2 connections at the other end of the cable. I assume one end connects to the fused junction block, but what about the other end?

I have searched all the other dual battery posts, and even looked at this diagram:

I just can't see where the second connection goes. Can any of you guys with the OEM setup tell me if you have this second connection?

Thanks!

chevyinside · February 13, 2009

rubber covered one goes to the sarter main terminal , uncovered one goes to the solinoid mounted on firewall

I pieced together the OEM dual battery kit from the dealer.

Here is a pic of the main positive cable:

Obviously one end connects to the battery, but then I have 2 connections at the other end of the cable. I assume one end connects to the fused junction block, but what about the other end?

I have searched all the other dual battery posts, and even looked at this diagram:

I just can't see where the second connection goes. Can any of you guys with the OEM setup tell me if you have this second connection?

Thanks!

chrisbmo2000 · February 13, 2009

rubber covered one goes to the sarter main terminal , uncovered one goes to the solinoid mounted on firewall

ummmmmmm......no the rubber covered one goes to the alternator and the other end to the starter....and no solinoid on the firewall this is gm not ford

OmarR · February 13, 2009

Actually, there is a stock solenoid:

And this is the cable that connects between the solenoid and the starter:

While I do appreciate the help from both of you, do you guys have the OEM setup in your truck that you can look at?

chrisbmo2000 · February 13, 2009

Actually, there is a stock solenoid:

And this is the cable that connects between the solenoid and the starter:

While I do appreciate the help from both of you, do you guys have the OEM setup in your truck that you can look at?

Really.......I guess you learn something new every day ....no I dont have the setup in my truck...sorry but a simple "in series" set up should work fine....Ive done it on lots of the older trucks Ive owned...and now I "see" where i "messed" up this is an 00 right? my 97 is still "old school" I forgot they changed alot after that.

chevyinside · February 13, 2009

yes acctualy i do , i have a 1500 hd with daul battery package , i was just looking at this today .mine doesnt run to the alternator it runs to the starter and charges from there .ok the red ones the bat +,black booted one goes the the fuse or cuircit braker other one goes to the solinoid the one from the starter goes to the same teminal on the solinoid . id take pics but it mostly covered by the battery

Actually, there is a stock solenoid:

And this is the cable that connects between the solenoid and the starter:

While I do appreciate the help from both of you, do you guys have the OEM setup in your truck that you can look at?

Really.......I guess you learn something new every day ....no I dont have the setup in my truck...sorry but a simple "in series" set up should work fine....Ive done it on lots of the older trucks Ive owned...and now I "see" where i "messed" up this is an 00 right? my 97 is still "old school" I forgot they changed alot after that.

OmarR · February 13, 2009

Sorry guys..I should have stated that my truck is an 03.

Keith, thanks for the help. Can you tell me if you have either 8B0, TP2, or TQ3 in your RPO codes?

If I am understanding you correctly, the main cable, UN-booted small end (my first pic) goes to the SAME terminal (on the solenoid) as the "solenoid to starter cable"

What about the other side of the solenoid and the other side of the fuse block? Do they connect to each other? I am just trying to see if you have the isolated or non-isolated setup, as i am trying to do isolated with the ignition off.

Actually, if you could get ANY pics, it would help me out alot. But I understand if it's too difficult.

In the end, I may just do:

Main cable to solenoid

solenoid to starter.

Wire up solenoid connector to either IGN1 or IGN3.

But at this point, I just want to see how the factory wired up the isolated version. With the cables having fusible links, it seems like the fuse block is redundant if it is only going inline with the rest of the wiring. But if the fuse block is "T"-ing off, with the other side being left open to add power for a plow, aux lights, etc...then that would make more sense.

I hope that made SOME kind of sense.

chevyinside · February 13, 2009

I have a tp2 , it is an isolated circuit cause it cuts the currant to the battery when its off. it looks like the fuse is there for you to be able to addd circuits to . i'll try to get some pics tonight .

Sorry guys..I should have stated that my truck is an 03.

Keith, thanks for the help. Can you tell me if you have either 8B0, TP2, or TQ3 in your RPO codes?

If I am understanding you correctly, the main cable, UN-booted small end (my first pic) goes to the SAME terminal (on the solenoid) as the "solenoid to starter cable"

What about the other side of the solenoid and the other side of the fuse block? Do they connect to each other? I am just trying to see if you have the isolated or non-isolated setup, as i am trying to do isolated with the ignition off.

Actually, if you could get ANY pics, it would help me out alot. But I understand if it's too difficult.

In the end, I may just do:

Main cable to solenoid

solenoid to starter.

Wire up solenoid connector to either IGN1 or IGN3.

But at this point, I just want to see how the factory wired up the isolated version. With the cables having fusible links, it seems like the fuse block is redundant if it is only going inline with the rest of the wiring. But if the fuse block is "T"-ing off, with the other side being left open to add power for a plow, aux lights, etc...then that would make more sense.

I hope that made SOME kind of sense.

OmarR · February 14, 2009

it looks like the fuse is there for you to be able to addd circuits to

So on yours, there is nothing connected (from the factory) to the other side of that mini fuse box? If not, then that makes a lot of sense and all of my "OEM" confusion is gone. Heck, if that is the case, I wouldn't have ordered the fuse box, fuse, and I would have just snipped off the extra cable "T"-ing off from the main positive cable.

One last question....where does it ground at? I know I can find or make a good ground myself, just curious as to where the factory ground is.

Again, I really do appreciate your help! The pics would be nice, but no biggie if you can't!

Gryphon · February 14, 2009

On this topic, any idea where I can find the second battery tray? It looks like it would meet my needs for mounting some accessories cleanly in the engine compartment.

OmarR · February 15, 2009

any idea where I can find the second battery tray?

The part number is 15246518. Any online dealer or local dealer can get it for you.

Gryphon · February 15, 2009

Excellent, thanks!

OmarR · February 18, 2009

Excellent, thanks!

No problem! And to everyone else, thanks! I got everything wired up!

typerod · December 14, 2010

Omar not sure if my PM went thru to you, but can you give a final breakdown of how you wired it up? Tthank you, Im trying to do the same setup! Where did you get your parts by the way? Thanks.

Excellent, thanks!

No problem! And to everyone else, thanks! I got everything wired up!

5Alive · June 29, 2011

I received a PM about this a couple of years ago, that I only today read. I clicked on the link in the PM, and once I saw the picture of the wire, I remembered what I ran into when I did this, so am adding to this thread to help someone else in the future.

The 3 eyelet wire in question goes from Battery to MegaFuse terminal to Solenoid. The unbooted eyelet goes to the megafuse terminal. The GM diagram shown is DIFFERENT than the application for which that particular GM 3 eyelet terminal was made. The difference is that the wire harness Omar bought INCLUDES a built in fusible link. The GM diagram shown does not. The fusible link in the harness Omar pictured replaces the purpose of the megafuse that the GM diagram shows. In GM applications that have the harness Omar pictured, the megafuse is downrated to 40 amps, and simple limits the current to the output circuit of the aux batter that is sent to the underhood electrical center on the driver's side.