2012 Columbia, no trailer signals

Discussion in 'Freightliner Forum' started by Elroythekid, Oct 19, 2021.

  1. Elroythekid

    Elroythekid Road Train Member

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    No right side trailer signals, left works, checked at the plug, dead there. As I said, left works right doesnt, truck works. Are there separate fuses? Where r they located? Checked the dash fuse box, nothing marked trailer signal, nothing in the b pillar?
     
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  3. RocketyMan

    RocketyMan Medium Load Member

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    Need to investigate wiring further upstream of 7-way.

    Post last 6 of vin and I'll give you schematic.
     
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  4. Elroythekid

    Elroythekid Road Train Member

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    Bt2084, wiring looks good all the way up to the loom under the hood. Cant find trailer signal fuses? Trl marker and tail in main box pass side dash. Only trailer fuses there. Called my local dealer, they had no idea. No trl fuses in b pillar, no box I can find on the firewall?
     
  5. RocketyMan

    RocketyMan Medium Load Member

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    Okay. The PDM has circuit breakers and relays. Sometimes these do go bad, but I'm thinking it's only your TRAILER right turn signal that is not working...?

    You have a couple intermediate connectors before they go to the BH connector on the FW.
    Per your configuration, your 7-way wire colors should be like this:
    upload_2021-10-19_14-1-38.png

    Pay attention to connector orientation:
    upload_2021-10-19_14-1-48.png

    The intermediate connector should be located somewhere in the RH frame rail:
    upload_2021-10-19_14-12-53.png
    They'll look like this in the frame rail:
    upload_2021-10-19_14-26-34.png

    The connectors are labeled as such:
    upload_2021-10-19_14-28-59.png


    That harness runs up the frame rail and into the BH (youre looking for 30 pin connector):
    upload_2021-10-19_14-20-56.png




    You are looking for CIRC 38R for the right turn signal. Can you answer if it is only the TRAILER signal that doesn't work?

    Lets start here. Next we can dive further if necessary.

    280
     
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  6. Elroythekid

    Elroythekid Road Train Member

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    It is only the right trailer signals. All other lights are working perfect.
    Are there fuses for the trailer signals? I certainly cant find them. I was hopeful that was the problem
     
  7. RocketyMan

    RocketyMan Medium Load Member

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    You have relays and breakers.

    Since it is ONLY the trailer lights, it makes me think it is the intermediate connector in the frame rail (could also be a splice--but lets not worry about that yet). Did you inspect this yet? If the tractor turn lights are working fine, then there is no need to worrying about any breakers/relays--granted everything is stock.
     
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  8. Dave_in_AZ

    Dave_in_AZ Road Train Member

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    Relay that controls the right side turn signal.
    Located on cab chassis controller on firewall.

    Tap it or push on it. Hope it's note the board. $2K.
     
  9. Elroythekid

    Elroythekid Road Train Member

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    Halifax Nova Scotia
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    20211020_110455.jpg
    Had some time today to have another look at it. First load a t a dedicated company, times are tight...
    I wanted to go over it o e more time and check all fuses etc. I opened the door in the B pillar, none of the fuses are marked trailer, I checked it all again, I t was all good, but when I looked at the trailer I had flashers. So, closed it all up and had none. It's something in the PDM. I couldn't get them to come back in, so I spliced a line into the trailer cord from the side blinker on the tractor and off I go. I ordered a PCM from my dealer back in Dartmouth, he found one. I've had trouble with that when I first got the truck the cab was leaking into it. I dried and cleaned it, maybe it's time. It's not an expensive fix so I'll try that first when I get home in a couple weeks. The cover is missing so maybe it was labeled differently?? If not I dont have brake and signal fuses separate for the trailer.
     
  10. Elroythekid

    Elroythekid Road Train Member

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    Halifax Nova Scotia
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    I dont have a chassis controller. Main fuse box, and a PDM in the B pillar.
     
  11. Elroythekid

    Elroythekid Road Train Member

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    Halifax Nova Scotia
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    @RocketyMan The PDM in the B pillar has nothing labeled trailer, could it still control the trailer signals and brake lights? They are the only trailer fuses I haven't found? Or do they just come of the regular signals and brake lights?
    How would i find out?
    Your diagram it looks like the trailer cord goes up the right chassis rail, mine looks like it heads up the left side?
    It's a glider kit, would that make a difference?
    Thank you for all your help, last couple days have been hectic, new job and all, and after all the calls I've made and heard back from zero of them, you actually answered and gave me info, cant possibly thank you enough.
     
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