2002 Pete 379 Battery/brake issue

Discussion in 'Peterbilt Forum' started by sloshed, Sep 20, 2024.

  1. sloshed

    sloshed Light Load Member

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    I have a 2002 Pete 379 (C15) and recently went to change my batteries and noticed this on both my positive and negative jumpers.
    1.jpg
    However, the ones that broke weren't just your basic jumpers but had a pigtail coming off it like so
    batt.jpg

    I have no idea where that pigtail goes to or what it is for but I figured it'd be a simple fix. Well local parts places only have the basic jumpers and Rush Peterbilt tells me apparently the ones I have are obsolete and no longer made as they only have the new and improved ones with a more robust and bigger connection... gotta have their $3.5k harness for that tho...

    So after searching a few junk yards to no avail I ended up welding the broken contacts back together for a temp fix. This worked as far as starting the truck and it running but now my brake lights do not work. I don't think it's a coincidence. At first if I pushed on the brake pedal really hard or held the trailer brake down they did somewhat work but then that quit and as of now the brake lights flat don't work at all.
    The turn and running lights do work, it's only the brakes on both the truck and trailer that are a no go.
    I also noticed that if I have the rpms up and on cruise control neither the brakes or the trailer brake no longer cancel the cruise control.

    So can anyone tell me where those leads off the battery jumpers go and does my brake light issue sound like a stop light switch gone bad or a relay or both or are these lead/connections perhaps shot from the welding? If I don't respond for a bit it's cuz I have to take a nap before being up early. :sleepy2::sleepy2::sleepy2:
    Thanks in advance for your time.
     
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  2. skallagrime

    skallagrime Road Train Member

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    The 2nd small pigtail looks like a heavy duty single pole deutsch connector, just do a line splice there (or clip close to the terminal connector) and put an appropriate ring end on it, then buy or make the simple single jumpers.

    If everything had been fine before you messed with it, your patch probably just did more harm than good, especially since youve now introduced a battery that was probably only intermittently being charged/used
     
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  3. bad-luck

    bad-luck Road Train Member

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    The pigtail on my 2000 goes to the ECM.
     
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  4. sloshed

    sloshed Light Load Member

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    ah so the weld is likely causing an intermittent connection - I will start there thank you

    could the welding to the battery terminal connector end possibly have messed up the deutsch connector as well?
     
  5. sloshed

    sloshed Light Load Member

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    Thank you I've been wondering this and was about to call a shop or two to find out. The guy at Rush wasn't much help and didn't know where it went to. Hopefully I've not messed up my ECM with this intermittent connection.

    edit before someone asks*
    yes I did the welding on the jumper terminal connector disconnected off the truck :p
     
  6. Ridgeline

    Ridgeline Road Train Member

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    That cable end is the wrong end; you need one with more surface contact area. The second one is made to provide that.
     
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  7. sloshed

    sloshed Light Load Member

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    right that's what I was figuring about the new ones... they have a thicker gauge wire and better connection than the 2002 ones
     
  8. sloshed

    sloshed Light Load Member

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    I don't want to buy and install a whole new $3,500 harness just to connect the deutsch connectors from the ecm to the battery cuz a 22 yr old battery terminal connector broke tho lol
     
  9. bad-luck

    bad-luck Road Train Member

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    Your welcome. I would think you would get a check engine light, with a fault code for intermittent power to the ECM.
     
    sloshed Thanks this.
  10. skallagrime

    skallagrime Road Train Member

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    If you want to look at it another way

    If you buy this kit for 1000$ you can now fix deutsch connectors up to 6 awg, buy refill items for it on digikey as needed.
    DTP/DTHD, Installer Kit w/2 Crimpers


    I have the awg 14 and smaller stuff, but REALLY want a good excuse to buy the bigger ones for power delivery
     
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