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MewshawManor's avatar
MewshawManor
Explorer
Jun 22, 2013

2007 Chevy 2500 HD Classic & Brake Controller Issues

After three days of failed attempts at making either of my brake controllers work, I have decided to make my first post.

Tow vehicle: 2007 Chevrolet 2500 HD Classic, 6.0L Gas, 4.10 rear end, 4x4

Trailer: 2007 Jayco Jay Flight 27.5 BHS

Brake Controller: Hayes Genesis

I decided rather than order a brake controller, I’d pick up a Hayes Genesis in person locally. I realize many folks use the Tekonsha’s, but I wanted something I could always source at an O’Reilly, Northern Tool, or other shop and I noticed the Tekonsha’s were hit or miss. I do have a backup Tekonsha Voyager I’ve owned and used for 10+ years. This post focuses on a problem occurring with either the new Hayes Genesis I purchased or my old Tekonsha Voyager.

The Genesis shows an error message “OC” (Open Circuit) when there is no trailer connected to the tow vehicle. This is the basic symptom, also exhibited by a lack of feedback on the Tekonsha Voyager when I try it.

- I used the harness recommended by Hayes (081780-HBC) and verified with them to be correct for my truck. There are two 2007 models and mine is the Classic.

- I verified the Hayes wiring chart to the corresponding plug under my truck’s instrument panel.

- There are two fuses that seem to matter: a 40A fuse that sends 12V to the trailer and a 15A fuse that powers the brake controller. Both visually check out fine and with a meter.

- I can measure power back at the 7-way plug on my bumper. I stopped by two trailer places and they said “looks like your controller and plug are working.” So I hooked up a light tester myself to each lead and have tested brake lights, power to electric brakes… It looks like it should work. When I hit the manual button on my controller, I see power coming through the correct pin on the truck’s rear connector.

- I tried my truck to another friend’s trailer that is known to be working. Same results.

- A friend towed our new fifth wheel to our house. Trailer worked fine with his controller. A neighbor stopped by and tested his controller to our trailer, also fine.

I’m open to any ideas…. What else should I check?

7 Replies

  • Helmsey's avatar
    Helmsey
    Explorer
    Jun 23, 2013
    There was an issue with the classic body style trucks and some of the wiring rubbing and shorting out. Are you using the trailer wires that Chevy provided to install the bed plug? If not, there is a bundle of wires zip tied to the frame on the drivers side, right where the cab meets the bed. It is possible there is moisture in the bundle of wiring and it is causing a short. When I put my P3 in my truck, I would initially get an alert about a short in my brakes (don't remember exact error now) and that bundle of wires was the problem. But in my case, the error would go away and brakes would function when I hooked the camper up.
    With a multimeter I figured out that there was just over 2 volts feeding back over the "blue" wire to the brake controller and it was seeing a short in the system.
  • MewshawManor's avatar
    MewshawManor
    Explorer
    Jun 22, 2013
    I have made an interesting discovery. The brake controller manual says if you keep receiving the OC error you can put the controller in PH or EH modes which is basically electric/hydraulic actuated mode. When I put the controller in PH mode, I can manually apply the brakes (and they work great) on my trailer.

    The big question is why? Why do I get an "Open circuit" and things don't appear to work in normal mode, but in PH mode (electric actuated hydraulic), the trailer brakes work fine? How can I determine if I have electric actuated hydraulics? The book with my trailer says I could have one of three types, but doesn't tell me how to determine.
  • jaycocamprs's avatar
    jaycocamprs
    Explorer
    Jun 22, 2013
    Some where you have a marginal conection. It will pass voltage at very low amps, light a test light or show on a meter. But will breakdown under load. The most likely place is at the plug, but it could really be anywhere
  • MewshawManor's avatar
    MewshawManor
    Explorer
    Jun 22, 2013
    mayo30 wrote:
    What are you expecting to see?Does the open circuit go away when hooked to the trailer at all.Do the brakes work,can you hear them activating when you try it hooked up but not moving?Guess I really don't understand the problem.


    The brakes aren't working. The open circuit message doesn't go away when I connect to any trailer.

    My truck, when connected to either of the two trailers I have available to test (my new 5th wheel and a friend's flat bed), does not activate the electric brakes.

    The hazards, turn signals, and brake lights work.
  • mayo30's avatar
    mayo30
    Explorer
    Jun 22, 2013
    What are you expecting to see?Does the open circuit go away when hooked to the trailer at all.Do the brakes work,can you hear them activating when you try it hooked up but not moving?Guess I really don't understand the problem.
  • MewshawManor's avatar
    MewshawManor
    Explorer
    Jun 22, 2013
    christopherglenn wrote:
    clean the contacts on the 7pin.


    Good suggestion, but I've also tried that.

    What I did to clean it was two things:
    1. Sprayed a little contact cleaner on them and then plugged in and adapter and pulled it out a few times.

    2. Also tried a little WD-40 in there.

    I'll take all the help I can get.

    I'm really considering going to town and buying a new harness to replace the factory plug on my bumper.

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