GMPP Fuse Box and AWW Harness Power Connections in 69 Camaro

[jorgezee1]

Hello,

I am starting the layout for rewiring my 69 camaro with a LS3 GMPP Connect and Cruise and a AWW update harness.

Configuration Notes: LS3/T56, GMPP Harness, AWW update harness, battery will remain up front, GMPP Junction box will be installed on the inner fender near battery.

I have a question and looking for recommendations for main power to the AWW harness from the GMPP fuse box vs the Starter.

AWW instruction would like you to connect the Alternator power wire to the Starter lug and the Engine bulkhead connector to the same lug. Both of these have fusible links.

The GMPP box has 3 lugs for power. a side post and two top post labeled A and B.

In the GMPP instruction I will be going directly from the battery to the GMPP box with a 8 gauge wire and I will use the side terminal in the GMPP box.

Could I just use the two other lugs as a junction point for the AWW harness and omit the Starter junction? I would like to get your opinion or what others have done.

[dhutton]

Hello,

I am starting the layout for rewiring my 69 camaro with a LS3 GMPP Connect and Cruise and a AWW update harness.

Configuration Notes: LS3/T56, GMPP Harness, AWW update harness, battery will remain up front, GMPP Junction box will be installed on the inner fender near battery.

I have a question and looking for recommendations for main power to the AWW harness from the GMPP fuse box vs the Starter.

AWW instruction would like you to connect the Alternator power wire to the Starter lug and the Engine bulkhead connector to the same lug. Both of these have fusible links.

The GMPP box has 3 lugs for power. a side post and two top post labeled A and B.

In the GMPP instruction I will be going directly from the battery to the GMPP box with a 8 gauge wire and I will use the side terminal in the GMPP box.

Could I just use the two other lugs as a junction point for the AWW harness and omit the Starter junction? I would like to get your opinion or what others have done.

I would not do that. Keep potentially noisy circuits away from the GMPP power. Also the current rating of those GMPP studs is likely not specified.

Don

[jorgezee1]

Don,



Thanks for the feedback! Would you recommend I just follow the AAW diagram and leave teh Alt and bulkhead connector to the LS3 starter lug? Or is there a better method?

[jorgezee1]

I have a spare 98 Chevy C1500 engine harness with fuse box and it appears to be identical to my GMPP box from the connect and cruise. These boxes have quite a few rather large gauge wires. The box seems it would house a fair amount of circuits. I am just try to see if I can use this huge GMPP box for other things. I will note that the 98 truck harness does not have anything connected to the two lugs only the side post lug going directly to the battery. The 98 truck Alternator also just goes directly to the battery.

Would it work if I did the following.

ALT to BAT ( 6 gauge)
BAT to GMPP Box (8 Gauge)
Use a 50AMP ACC 1 Fuse from the GMPP box to power the bulkhead connector (10 Gauge stock AAW wire)

Would this still introduce noise and not be correct?

[badazz81z28]

I kept mine separate...I have a heavy gauge wire coming from the battery that is spliced into each harnesses main power feed. Which is all spliced together with the alternator. My battery is in the trunk, so they are not directly connected to the battery per-se. The lugs on the GMPP box are more for fused power for the fans...not your vehicle harness.

[dhutton]

Don,

Thanks for the feedback! Would you recommend I just follow the AAW diagram and leave teh Alt and bulkhead connector to the LS3 starter lug? Or is there a better method?

Yes I would follow the instructions.

Don

[jorgezee1]

I kept mine separate...I have a heavy gauge wire coming from the battery that is spliced into each harnesses main power feed. Which is all spliced together with the alternator. My battery is in the trunk, so they are not directly connected to the battery per-se. The lugs on the GMPP box are more for fused power for the fans...not your vehicle harness.

Did you add fuses in between the each power feed and the battery or is it direct?

OK, I guess I have to stop trying to use the GMPP box for anything but the LS3 engine swap and fans as it seems like it may not handle the power or cause issues.

I guess I should state what I am trying to solve or not really solve but clean up.

I was trying to eliminate the amount of power cables directly to the battery or to the starter lug and utilize what I thought was a power distribution box (GMPP box) like what the was done on the older Vortec equipped truck/vans (basically try to copy my C1500 pickup engine harness power wires).

Seems like I need to make a side post battery terminal with extra wires or a Junction box next to the battery to accept the main bulkhead harness, GMPP box, ALT and than just have the main starter wire direct.

[jorgezee1]

Here is a picture of the 98 Truck box, basically exactly the same.





I would like to place the GMPP box near the battery if possible. Not as cool as hiding everything, but I really just want everything easily accessible.

[jorgezee1]

Yes I would follow the instructions.

Don

Thanks Don, I think now I am just trying to think there was a better way.
It also seems like the AAW updated their instructions as well. The have a new version ("Second Design") of the 500686 Camaro harness that does not go direct to the starter.

I have the 1st version that goes to the starter but after googling this I found they have a revised setup going to a fuse block with 6 GA wires instead of going to the starter.



Adding Download links:

1st Design:
https://smhttp-ssl-87263.nexcesscdn....Design_1_1.pdf

2nd Design:
https://smhttp-ssl-87263.nexcesscdn....Design_1_1.pdf

[dhutton]

Those two layouts are essentially the same imho. One is just fused versus fusible links. The newer system also enables higher current.

Don

[jorgezee1]

Those two layouts are essentially the same imho. One is just fused versus fusible links. The newer system also enables higher current.

Don

Thanks Don.

I prefer the revised setup. My goal was to take the cables away from being installed on the starter. This will actually do that. I also need to figure out if I should up the wire from the Holley Alternator. I was thinking 6ga, but maybe 4ga would be better? The AAW kit uses a 8ga. Seems like most builds are using larger gauge wire for the Alternator.

I guess I’m referring to what may be called the Big 3 upgrade.

[dhutton]

Alternator wire should size should be based on alternator capacity. It never hurts to go too big.

Don

[badazz81z28]

Did you add fuses in between the each power feed and the battery or is it direct?

OK, I guess I have to stop trying to use the GMPP box for anything but the LS3 engine swap and fans as it seems like it may not handle the power or cause issues.

I guess I should state what I am trying to solve or not really solve but clean up.

I was trying to eliminate the amount of power cables directly to the battery or to the starter lug and utilize what I thought was a power distribution box (GMPP box) like what the was done on the older Vortec equipped truck/vans (basically try to copy my C1500 pickup engine harness power wires).

Seems like I need to make a side post battery terminal with extra wires or a Junction box next to the battery to accept the main bulkhead harness, GMPP box, ALT and than just have the main starter wire direct.

The cable that feed both harnesses fused. I think it's a 150amp fuse. Here a sketch.

[jorgezee1]

Guys is it recommended practice to put the battery in the trunk? I know this is becoming more OEM practice and Hot Rodder’s that want to lose front nose weight.

Is there any other benefit aside from weight savings? It seems to do so we would add a lot more wires and complexity.
I’m just trying to understand if it makes sense for me to do the change now while I’m trying to figure out how to wire the car. The car is not being tracked, nor going to drive it to its limits. I just want to cruise around my home and work and enjoy it.

[badazz81z28]

Guys is it recommended practice to put the battery in the trunk? I know this is becoming more OEM practice and Hot Rodder’s that want to lose front nose weight.

Is there any other benefit aside from weight savings? It seems to do so we would add a lot more wires and complexity.
I’m just trying to understand if it makes sense for me to do the change now while I’m trying to figure out how to wire the car. The car is not being tracked, nor going to drive it to its limits. I just want to cruise around my home and work and enjoy it.

People do move the battery to the trunk to help with weight distribution and in some cases a necessity for space. Me personally, my battery is in the trunk for space. My oil tank is located where the battery was. There was really no other place to put it that would accommodate the length and girth of it. My intake and filter is on the driver side...so the battery had to go somewhere. I would have left it in the engine bay if I could have.

[jorgezee1]

Thank you for your input and help guys!

I believe I have a better idea of how to wire the power side of the system. I hope to be able to use some spare parts I have laying around for this configuration.

battery will remain in the stock location.
optima 34/78 yellow top
I will be using a GM Starter Cable from a LQ based truck. Likely I will shorten it. I like the red box as a another option for power distribution if needed, but I can omit it of it becomes to cluttered.



The cable has a red power box installed on it. I will tap into this and use it to feed the GMPP box. I bought a set Megafuse holders on ebay off a Jaguar JX8.



Battery directly to the starter
Starter to MegaFuse
Alternator will connect to 175 AMP Megafuse.
AAW Harness with 175 AMP Megafuse.
GMPP to Red Bat box via - Direct, MegaFuse or Fuseable link?

Here is an Example:

This example only has one megafuse, but I would have two.
The Battery cable is a single cable going to the starter with a box crimped in the center of it.


Placement will be something like this in the Camaro:
All the existing AC lines, heater lines and overflow will not be there. I will be rerouting them.
I do have a Vintage air kit, but still debating if I should just use the OE AC since everything functions and already is converted to R134.




Any feedback on this setup?

[dhutton]

That should be fine imho.

Don

[jorgezee1]

Don, what would be considered a noisy circuit?

I would like to use the GMPP box to power my Headlight relays. I am trying to understand what should not go into the GMPP box.


I modified the GMPP box a bit and added the PCM of NC fan control and AC bump. I took apart my spare truck harness and used some of the connectors to add some circuits.
I would like to use this to power the Horn relay and headlight relays, but I will wait for experts to chime in.

The PCM of NC kit is really nice and straight forward to install. I ran into a issue with one of their cables crimped with the wrong terminal. I called them and they are sending me a correct wire. For now I modified the one I had to verify the relays and everything was working.

Unmodified GMPP box




PCM of NC kit



Wrong connector




Modified GMPP Box with added circuits







PCM of NC references:

https://www.pcmofnc.com/product/gmpp...ric-fan-kit-3/

https://www.pro-touring.com/threads/...-Electric-Fans

https://www.pro-touring.com/threads/...-camaro/page12

[dhutton]

Should be ok but honestly I don’t connect anything to the ECM power that doesn’t need to be there. One of those risk/benefit analysis things...

Don

[andrewb70]

Link for PCM of NC?

Andrew