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Fitting a brake controller

LMM: 
4K views 21 replies 7 participants last post by  cptdondo 
#1 · (Edited by Moderator)
I need to install a brake controller for a 2 axle trailer. I'm wondering if there are any wiring stubs or connections that would make this easier.

Anyone know if it's possible to install the factory controller?

Thanks!
 
#4 ·
#7 ·
Van chassis don't have it :(
 
#8 ·
check on the medium duty board, there are multiple posts about this. I believe the wiring location is on the passenger side of the truck, located on the frame rail. Do not wire up the brake signal wire to the brake switch, this will cause problems.
 
#9 ·
So the instructions say:

Red Wire (Vehicle Brake light) ConnectionThe requirements for a suitable connection of a brake controller trigger wire are quitespecific. This connection point must:• Provide battery voltage output while the vehicle brakes are applied.• Have 0 volts output while the vehicle brakes are not applied• Accept battery voltage input when the brake controller manual over-ride is operatedand illuminate at least the trailer brake lights.

Where do I find a suitable location for this? Any ideas?
 
#10 · (Edited)
2010_GH_Van_Elec_1_7_D1_100813.pdf

Page A-1
Trailer Wiring on Cutaways – RPO UY7 On 33803 vehicles (3500 Cutaway with 159 in w/b), Trailer Wiring (UY7) is now available with the 6.0L (LY6) gas engine, in addition to the 6.6L (LMM) diesel. •

Page A-32
ElEctrical Manual – 2010 G/H Full SizE Van
PAGE
A-32
Electrical Manual – 2010 G/H Full Size Van
Trailer Wiring Harness (UY7)
The optional heavy-duty trailer wiring package (UY7) includes a wiring harness, with a seven-pin connector at the rear of the vehicle and a four-wire harness assembly under the driver side of the instrument panel. The four-wire harness assembly comes without a connector.
If your vehicle does not have a trailer hitch, the seven-wire harness assembly with connector is taped together and located in a frame pocket at the driver side rear left corner of the frame. If your vehicle has a trailer hitch, the seven-wire harness assembly with connector is attached to a bracket on the hitch platform. In both cases, the seven-wire harness has a connector and includes a 30-amp feed wire.
The seven-wire harness connector contains the following trailer circuits:
• Light Green: Back-up Lamps (10A fuse)** • White: Ground • Dark Blue: Trailer Brake Signal • Dark Green: Right Rear Stop and Turn Signal* • Red/Black Stripe: Battery Feed (30A Fuse) • Brown: Trailer Park Lamp Supply Voltage (15A fuse)** • Yellow: Left Rear Stop and Turn Signal *
The four-wire harness (without connector) contains the following circuits:
• Black: Ground • Red/White: Battery Feed • Dark Blue: Trailer Brake Signal • Light Blue: CHMSL/Stoplamp Supply Voltage
* If your vehicle is a cutaway with trailer provisions, a 15 amp fuse will be shared for both left/stop trailer turn and right/stop trailer turn signals. However, the cutaway lighting connector will have a 10 amp fuse for each signal.
** If your vehicle is a cutaway with trailer provisions, a 15 amp fuse will be shared for trailer park lamps and cutaway rear lighting connector park lamps. Also, a 10 amp fuse will be shared for trailer back-up lamps and cutaway rear lighting connector back-up lamp.
 
#13 ·
That's only IF the UY7 option was ordered with the chassis. The RPO code list is at the bottom of the passenger door, IIRC.
 
#16 ·
Electrical/body manual helped me a lot on mine,
When i got it it was 'dismounted' roughly, so most anything back of the cab proper was cut.
Easy enough to see what it is supposed to be.
 
#17 ·
Would connecting to the brake lights work? That's about the only place I can think of that meets all the requirements. The harness I have has a module that powers the trailer lights separately so current draw should not be a problem.
 
#21 ·
I'm assuming that you downloaded the PDF info from GMUPFITTER. The entire file is searchable so just look for what you want. Very well may be multiple finds withing the manual.
 
#22 ·
So for posterity here's what I ended up doing:

Installed a universal trailer harness from etrailer: https://www.etrailer.com/Wiring/Tekonsha/22550.html . Then installed a Redarc Tow-Pro Elite brake controller, splicing in to the harness after the power module. Works just fine.

I was not able to use the X405 connector as the upfitters cut it off and made a mess of the OEM wiring. I didn't have room to splice into it.
 
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