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07Sierra07

07 Nbs Trailer Brake Wiring?

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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?

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

 

Document ID# 1866253

2007 Chevrolet Silverado - 4WD

 

 

--------------------------------------------------------------------------------

 

 

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

 

 

 

 

--------------------------------------------------------------------------------

 

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.

 

 

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

 

© Copyright General Motors Corporation. All Rights Reserved.

 

 

--------------------------------------------------------------------------------

Document ID# 1866253

2007 Chevrolet Silverado - 4WD

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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.

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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."

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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

truckwiring.jpg

 

 

Here's the trailer brake controller's wiring:

connections.jpg

 

Here's the blurry final connections shot:

trailerwiring.jpg

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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

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

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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!!!

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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!

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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.

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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.

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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!!!

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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!

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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.

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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.

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