Okay, first Ill name my equipment...
05 Chev DMAX Longbed 4wd
06 Ragen 21ft FK Toyhauler
Tekonsha Trailer Brake controller

Now comes the issue...

I have no brake light or blinker on the drivers side of the trailer only when the lights are off on the truck, yes the truck blinkers and brake lights work fine. Also getting adequate amperage from the plug on the truck. When the lights are on, I have lighting on that side, but no brake or blinkers. All fuses and busses appear to be in good working order. All grounds and wires in good condition. Heres what gets me, my neighbor hitched up w/ his F150 and it worked fine. Another friend said he had the same problem w/ his Suburban, when I asked how he fixed it... He said he bought an F250 Since Ford is a four letter word in this house, Ill just try to find the problem. Any help is appreciated.

foord?

does the brake light and turn signal on the truck work on that side? there are seperate fuses in the box under the hood just for the trailer socket, id check those as that could be a likely cause

J.K.

Yes all in working order and have been replaced anyway to make sure

wonder if the malfunctioning mirrors and this have something in common? does the LED signal in the drivers mirror work ok?

LED works fine, I dont think theyre related. The mirror issue seems to be mechanical, was sticking a bit befor it got stuck. You can still hear the motor trying to work in the mirrors

do you have another trailer to try the truck with? maybe a problem at the socket on the truck

Shouldve mentioned this before I towed a boat on vacation and everything worked fine! The only difference is there were no trailer brakes on the boat trailer

The problem is that they had two different pinouts on the trailer plug for the brake controller.
Don't even ask how I know..

Huh??? How do I fix it?

"I took a volt meter at the trailer brake controller harness and checked for voltage, found your twelve volts hot.
Then turned on the lights to find the hot with the lights on.
Then I pressed the brakes to find the hot with the brakes on.
Then I found the turn signal hots.
Then I pulled the lock on the truck side of the brake controller harness that releases the wires, and redid the pinout,....... "

From The Computer Guy... Thanks!!

Don't get two happy till it works. Did you install the brake controller..
Click to view attachment
The blue thing is the pin I am reffering too

Do you leave the harness plugged in or will it work unplugged?

another board member had it done for me along w/ a bunch of service work when I first got the truck.

The blue thing on the red plug in the pic??

you fix the brown plug then replug it in, you will need the brake controller install manual.
Do you still have my number, call me, I don't think I explained it well.

http://www.tekonsha.com/instructions/BC%20Wiring.pdf

He's out there messing with it right now

Nick (npertric) and I ran into a funky issue with the adapters, typical 7-6 style . On some the LT turn/brake lights wouldn't work and they would keep the brakes partially engaged all the time. While others worked just fine. So, we disassemble a couple of them and found that they weren't all wired the same.. Brand new too!

2002 and down had different pinouts then the 2003 and up.....
Which was beyond uhaul.....

Check out the last post here.

http://www.glamisdunes.com/invision/index....rake+controller

if the pin oust were incorrect the trailer lights and etc would not have worked correctly prior to this....

QUOTE Trailer Brakes Applied When Headlights/Park Lamps Are On, Brake Controller Illumination (Modify Brake Controller Wiring Harness) #02-05-22-004C - (Apr 5, 2005)

1999-2005 Chevrolet Silverado

2000-2005 Chevrolet Suburban, Tahoe

2002-2005 Chevrolet Avalanche

1999-2005 GMC Sierra

2000-2005 GMC Yukon, Yukon XL

2003-2005 HUMMER H2

This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 02-05-22-004B (Section 05 -- Brakes).

Condition

Some customers may comment that when the headlamps or park lamps are on, the brakes on the trailer are always applied, or that the back lighting for the trailer brake controller only illuminates when the brakes are applied.

Cause

The cause of this condition may be due to wiring changes within the vehicle electrical system for the 2003 model year.

Correction


Inspect the brake controller wiring harness jumper that is plugged into the vehicle relay block-body. The relay block-body is located under the left side of the instrument panel near the left kick panel, behind a plastic cover.

The 1999 though early 2003 wiring harness jumper that plugs into the relay block will have a reddish/brown 6-way connector and a tag with the last four digits of the wiring harness part number. Second design 2003-05 may have a white plastic connector with part number 5418 as well.

• The 1999 jumper is/was P/N 12171982 with a pink/purple tag identifier of 1982. This number has been superseded to 15366255, with a pink/purple tag identifier of 6255.

• The 2000 jumper harness is P/N 15366255. The pink/purple tag identifier is 6255.

• The 2001-2002 jumper is P/N 15086884. The orange tag identifier is 6884.

• The 2003-05 jumper is P/N 15085418. The orange tag identifier is 5418.

When transferring the brake controller with the wiring jumper attached from a 2001-2002 vehicle to a 2003-05 vehicle, a change to the jumper harness connector must be performed.





The following information is for the 1999-2002 wiring harnesses.

Pin
Wire Color
Circuit Number
Function

A
LT BLUE
1620
Stop lamps

B
RED
142
Brake controller 12 volt source

C
DK BLUE
47
Brake Controller output (Trailer Brakes)

D
BROWN
2409
Brake controller illumination

E
--
--
--

F
BLACK
1850
Ground


The following information is for the 2003-05 wiring harness.

Pin
Wire Color
Circuit Number
Function

A
BROWN
2409
Brake controller illumination

B
RED
242
Brake controller 12 volt source

C
DK BLUE
47
Brake Controller output (Trailer Brakes)

D
LT BLUE
1620
Stop Lamps

E
--
--
--

F
BLACK
1850
Ground


To modify a 12171982, 15366255 or 15086884 harness for use in a 2003-05 vehicle, switch the wires in cavities "A" and "D".

To modify a 15085418 harness for use in a 1999-2002 vehicle (see model list at the front of this bulletin for applicable models), switch the wires in cavities "A" and "D".

Warranty Information
When the correct wiring harness P/N is matched to the specific model year of the vehicle, everything works properly. Therefore, conversion of an incorrect wiring jumper to match the vehicle would not be considered a warrantable repair.


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.

You said you had a white connector so this may not be your problem?
Maybe it's a bad relay?
I would check the voltages at the 7 pin, for lighting....

Fix it yet bro??

I'm talking about the one that plugs in at the bumper, this should be universal.

It sounds to me like the GM bulletin is for people who are taking there set up out of an early '03 and old truck and installing it in a late '03 and newer. The sub-harness comes with the truck from GM. Them changing the pin location in the junction box is what caused all the problems.






IF the PO reused the controller/harness out of an earlier truck. His is an '05, so it should be clear of any '03 mid production snafu..


At least that's how I read the bulletin.

Chebbys have separate fuses for the trialer circuits- right and left fuses too.

It could also be a bulb on the trailer with a damaged filament that hangs and crosses the other filaments- makes the lights to weird chit.

Okay, based on the above post w/ the link to the GM Bulletin regarding switching the pinouts..... it did nothing. I disconnected the brake controller completely and it was doing the same thing, that tells me it has nothing to do w/ the controller or the harness. All other lights worked w/ controller unplugged and still no left blinker on the trailer. Im so effin frustrated, any more ideas folks??

Is there a blinker signal at the hitch plug? The pin locations are on the cover.

CONTROLLER HARNESS AND PLUG ARE FACTORY FOR THE YEAR OF HIS TRUCK

ken if it worked with another truck then the problem is in your truck

did you check all fuses?
inline fuses?
did you check at the trailer plug with a test light if the blinkers work?
check both fuse panels in the engine and dash?
check wiring from plug to fuse panel?

Check to see if your 3rd brake light is working or not, you know the one on the rear of the cab up high.
If it's out, replace the bulb and that could fix your whole problem.

Could also clean the the pins on the truck plug. I little corrosion or oxidation can cause a bad connection.

ken check your pm's

I was having the same problem and it ended up being the 7 pin male connector. Used a small wire brush(pipe cleaner type) and cleaned surfaces well, bent the pins to make good strong connections and it has worked great ever since.

i had the same problem with my truck and trailor. for me it was a easy fix. all i had to do was replace my blinker relay to a high performance one. took care of the problem right away.