07 Nbs Trailer Brake Wiring?, Will my brake controller wiring from my 2004 fit my 2007 NBS? Options

[07Sierra07]

I removed my old brake controller form my 2004 Sierra and want to install it on my 2007 Sierra.
Does anyone know if the plugs in the box are the same?

[MS3DALE]

No,There is no longer a plug under the dash in the GMT900's,Read this bulletin.......

Document ID# 1866253
2007 Chevrolet Silverado - 4WD


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Subject: Information on Electric Trailer Brake Controller Wiring - Towing, Tow #06-08-45-008 - (10/10/2006)



Models: 2007 Cadillac Escalade, Escalade ESV, Escalade EXT

2007 Chevrolet Avalanche, Silverado, Suburban, Tahoe

2007 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL




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Some customers may have questions on how to connect an electric trailer brake controller or where the brake controller pigtail harness is located.

Starting with the new 2007 GMT900 full size utilities and pickups, there is no longer an electric trailer brake controller pigtail harness.

The trailer brake controller wiring is now part of the Instrument panel wiring harness and the blunt cut wires are located under the left instrument panel, behind the data link connector. There are four blunt cut wires in this harness as described below.

Wire Color
Circuit #
Description

Red/Black
242
12 Volt power supply (30A stud #2)

Dark Blue
47
Trailer brake output voltage

White
22
Ground

Light Blue
6311
Stop light input





The Red/Black circuit 242 must be connected to stud #2 of the 30 Amp fuse of the UBEC. This wire is located between the left fender and the UBEC (1). Refer to Trailer Connector/Provision Schematic in SI for document information on the trailer brake control-- Domestic.



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Document ID# 1866253
2007 Chevrolet Silverado - 4WD

[rex-r-us]

I am also wondering about adding a trailer brake controller to my truck also. I read somewhere that the NBS 2500HD & 3500HD will have factory installed controllers built into the dash. Could one of these be adapted to the 1500? Thanks.

[07Sierra07]

[quote name='MS3DALE' date='Apr 4 2007, 10:36 PM' post='459439']

Any chance you can help me with this?
1- Where exactly are the wires they describe in the bulletin?
2- What do they mean by 'stop light input' do they mean CMHST??
3- This part I really need help with "The Red/Black circuit 242 must be connected to stud #2 of the 30 Amp fuse of the UBEC. This wire is located between the left fender and the UBEC (1). Refer to Trailer Connector/Provision Schematic in SI for document information on the trailer brake control-- Domestic."

[07Sierra07]

OK. This weekend I installed my trailer brake controller.

Can anyone verify if this wiring sounds right?

Here's the wiring:

TRUCK WIRING Trailer Brake Controller Side
Dk Blue - Aux--------------->Blue Wire Brake Output to trailer.
Red/Black - BATT----------->+ Black Wire Positive
LT Blue/WHT-CMHSL-------->
ORN - CHMSL---------------->X Red Wire Cant read this, something side of stoplight switch
WHITE - GND- --------------->WHITE Wire Negative

Below their are 3 picturs.
The first pic is the trucks wiring harness
The second pic is the brake controller harness
The third blurry pic (sorry) is the completed connections.

If anyone can verify that this is correct.... before I install a fuse in the block to test it...... I would appreciate it.

Thanks,
07 Sierra 07

Here's the trucks wiring



Here's the trailer brake controller's wiring:


Here's the blurry final connections shot:

[07Sierra07]

I lost a little faith in my dealer today.
I took the truck in for a small issue with the power mirrors and asked them to verify that I had the wiring correct for the brakes.
They charged me .3 / hr labour which works out to about 30$ to take a 'glance' at it. They said it was right, but I'm still not certain. I just don't have faith in them. They also said that the wire does have to be connected to the fuse block "The Red/Black circuit 242 must be connected to stud #2 of the 30 Amp fuse of the UBEC." but also said that it doesn't need another fuse..... I read a post somewhere on the net saying that it does need another fuse in location 70??

Can anyone clear this up?
a- is the wiring above correct?
b- Do I need to install a fuse in loc. 70 or just connect the red black wire by the left fender to the fuse box?

Any help is greatly appreciated,
07 Sierra 07

[sonjaab]

TTT......For another lost soul thats looking for a clue!!!!!!!!!!!!!!!!

[Triki Dick]

TTT......For another lost soul thats looking for a clue!!!!!!!!!!!!!!!!

I made a bold attempt on Sat, however, it doesn't work.

So, I grabbed my meter,

power to fuse, yes
Power to Pole, yes
power to hot wire at pole, yes
power to hot wire under hood, no!!!

I have no juice to my hot wire under the dash, I doubt GMC snagged the wire when installing harness, why should't i get juice to the wire in the truck!!!

[USA1Fan]

I may get my hands smacked by the moderators for this (don't recall the policy here on linking to other forums just now, and it's been a while), but check this out. Avalanche owners have gone through the exact same pain. So far I haven't towed anything that would require a controller, and probably won't. But it's never a bad thing to know what needs to be done just in case..

Good luck!

[sonjaab]

This wire must be connected at the underhood fuse center as well as
the Maxi fuse installed to get the power wire under the dash hot !
As I understand this post by Dale...........

The Red/Black circuit 242 must be connected to stud #2 of the 30 Amp fuse of the UBEC.
This wire is located between the left fender and the UBEC (1).
Refer to Trailer Connector/Provision Schematic in SI for document information on the trailer brake control-- Domestic.

This post has been edited by sonjaab: May 1 2007, 11:40 AM

[Triki Dick]

That red/black wire is hooked up to pole2, with a 40a fuse in it. There is power to the wire!!

Now, I"m not going to start stripping tape off wire's to find where that red wire goes to. The wire I"m refering too was tape'd to the wire's below the Brake Booster! One red wire all by it's self.

I attached that wire and when I go inside there's no power to the wire under the steering column. Is this the same wire!!!

Now, I'm no pro, but I know how juice flows down wire's, and if there's power on one side, they should be power on the other side, asuming you have the right wire.

And, I am not going to let this little project send my truck to the dealer for them to laugh at me.

I'll be having another prayer meeting with mr beer and sierra tonight.

[Triki Dick]

I have figured it all out,...

Under dash, we know where those wires's go, bla bla.

Under Hood,

The wire taped under the brake booster, that's the wire to charge the battery on your trailer emergency brake.

There is another wire, taped to right of fuse box under hood, under that bundle of wires, all you'll be able to see is the white label. THATS THE WIRE THAT GOES UNDER THE DASH!!

You'll have to connect BOTH WIRE'S if you run a trailer battery.

DUH!

I feel stupid but heck, the people at the dealer could't figure it out either!!!

[07Sierra07]

WOAH, I never knew their were 2 wires....

I just went outside and checked under the brake booser and found the OTHER red/black wire...

Initially I found one wire between the fuse box and the fender and hooked it up... I didn't know that their was another one under the brake booster....

I was wondering why my trailer didn't charge last time.... and was worried cause I'm heading out camping this weekend.....

I'll connect the wire tomorrow night and test the connection at the rear bumper to verify....

Thanks!

[Triki Dick]

If you read your book it tells you ways to boost your Altinator charge.

Push tow button or turn lights on..

Mine took 10 mins to charge battery up.

[Chris B]

I have figured it all out,...

Under dash, we know where those wires's go, bla bla.

Under Hood,

The wire taped under the brake booster, that's the wire to charge the battery on your trailer emergency brake.

There is another wire, taped to right of fuse box under hood, under that bundle of wires, all you'll be able to see is the white label. THATS THE WIRE THAT GOES UNDER THE DASH!!

You'll have to connect BOTH WIRE'S if you run a trailer battery.

DUH!

I feel stupid but heck, the people at the dealer could't figure it out either!!!

I have found the red/black wire between the UBEC and the left side, but I see no wire under the master cylinder. Was there a change which integrated that wire. Plus, that gasket connector on the wire seems sized for the 40A stud, not the 30 amp stud.