Need assistance.. Electrical issues 2007 Volvo VNL

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by TCF, Apr 18, 2023.

  1. TCF

    TCF Light Load Member

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    That's what you are talking about... I have one of those... Use it for checking fuses when it's dark and I forget to recharge my headlamp... Thanks for the reminder...

    What wires are you wanting me to check? We are still talking about just the 7 way correct?

    It was suggested that I buy a 7 way tester and plug it into the trailer then plug my cord into it... See if it lights up..
    If it does... Then my truck is good and the chassis is trash..
    Sound about right to you? I know they are like $50 but if that's concrete proof that it's not my equipment causing me the issues than it's much easier for me to be able to reject loads and it not be my issue.

    Mostly do fedex and jb hunt so they aren't that bad to work with overall but just started pulling for kllm and we don't have a "relationship" with them... And most of the time with pool chassis... Once it leaves the rail... I'm personally responsible for roadside costs for it.... Which is why I like jb and fedex because they take care of their own stuff...
     
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  3. D.Tibbitt

    D.Tibbitt Road Train Member

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    Ive never used the 7 way tester before so i cant comment on how it works... You can do the same thing as that tester , with the test light.. Just clamp to a good ground. Like the shock bolt or fuel tank straps bolt. and then stick the probe into the truck plug brake light probe and see if it lights up.. The brake lights are on the bottom.. This how plug is routed. Brake lights are the red. Green and yellow is left and right turn signal.. Blue is abs. Black and black(should be brown on right but i dont have brown color of photo editor) is marker/clearence lights. White up top is ground....see picture below

    Screenshot_20230419-102357~2.png

    Use your test light to probe the bottom pin on the plug and if it lights up then the brake lights are working properly on your truck... If that is the case then plug in the cord to truck side of plug then use test light to probe the trailer side of cord... If this works then the cord is good... Plug into trailer and see if the brake lights work on trailer. If not then the problem is on trailer side .
     
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  4. TCF

    TCF Light Load Member

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    Yeah... That's what I was thinking...
    That 7 way one is the same thing... It's just a volt tester... If it lights up green then the circuit is "good"..

    20 chassis today so far and only 1 bad one..... Just 1...and it was an old pos dcli with the abs light on... A flat tire... Expired inspection and all...

    Wonder if it's possible I still have some sort of short or maybe they were all just bad...

    It's common knowledge they aren't actually inspected or taken care of... So if drivers don't report the issue then they don't get fixed.
    Just saw one with duct tape over the abs light... And I've picked up at customers before where there are several lights just missing....

    It's all just weird because yesterday that spotter pulled the box from the dock and dropped it right in front of me and I swear I saw the brake lights working fine for him..
    Still makes me think I have some intermittent issue.... But how do I find the gremlin when every time I check he's hiding?

    I'll bring my light tester and buy a 7 way to keep with me... And then I can check once I hook up to a bad one I guess.... Just weird...
     
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  5. D.Tibbitt

    D.Tibbitt Road Train Member

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    Its tough pulling different trailers all the time. Especially those container chassis . i heard they are pretty ####ty and abused.. I would just keep an eye on it. And if you continue to have problems dosn the line then report back here
     
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  6. TCF

    TCF Light Load Member

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    Thank you very much sir.... This is driving me nuts.
    Going to go for a wash tomorrow morning and see if the wet has any effect on any of it and talked to dispatch about finding a short run that they can definitely cover if I have the issues.... I don't want to leave them stranded but I also don't want to bobtail around for a few hundred miles to possibly find an issue...

    Maybe I got lucky and switching those sensors did the trick because #2 still has not thrown a code.... But I was just told "you are the most unlucky person I have ever met in my life.....its probably your truck.."
    So we will see..

    And I checked the plug ends.. Well one of them... Never seen this before but maybe it's the new standard for phillips.... They are in crimp connectors that are glued into the spot.

    Seems like a good way for glue to melt and a cable to fail.. But once again... I'm the worst electrician in America.
     
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  7. 2Tap

    2Tap Medium Load Member

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    Yes, smack that light controller into your palm and see if the lights do anything. Old analog controllers get goofy. Don't assume because it's new that everything is digital (circuits & transistors).

    When you say grease... a non conductive dielectric type grease i hope?



    Exactly! And no amount of testing will find faults/taps/shorts in that system until that connection is stressed to the point of disconnect. Analog/Direct current has many advantages with continuity being chief.

    We used to throw Nurse calls ( upload_2023-4-19_14-33-58.png ) away in hospitals because they are near impossible to find a fault in with an oscilloscope unless another tech was flexing the exact spot in the wire that was causing the intermittent disconnect. Once the call system detected that disconnect it reported and had to be reset.

    Continuity and voltages are therefore moot. The ONLY way i have ever discovered to quickly diagnose shorts/taps is to use an old school telco toner and wand. Get the wand with an earphone jack (more accurate). When you tone out each wire, assuming they are the same gauge/length and dont feed to other branches, the tone should sound very similar. When you have a sketchy connection/tap, you will hear the difference instantly.

    I'm not saying go buy this or it's going to fix your issue. You have every right to be agitated. Electrical problem can be very time/$$$ consuming.

    https://www.amazon.com/Fluke-Networks-26000900-Pro3000-Generator/dp/B000FTADX0?th=1

    That one doesn't have headphone jack.

    Sorry i couldn't be more of a help.
     
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  8. TCF

    TCF Light Load Member

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    I use this for grease... Works wonders...

    I think I get what you are saying and it kind of makes sense to me? Except the part about feeding into other branches?
    The 7way wire plugs into another spot that has connectors that plug into another spot that plug into other connectors.... So wouldn't that mess up the process?

    And I'm not sure "more helpful" is a thing?
    This isn't reddit so any response with any ideas even if they don't work are technically helpful at least to me...

    Half the responses were check the lines and fues and relay.... And I did all that before I even posted... But not everyone knows to do that since I see posts of people asking where the fuses are...
    So for me... I appreciate the response and the ideas..
     

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  9. 2Tap

    2Tap Medium Load Member

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    Assuming it's non-conductive which it states, you're good.

    I simply disregarded the other noise from what you stated. Fuses aren't intermittent but people are trying to help. Even if i were there with my knowledge and experience i realize the true enemy is time & money. If those wheels aren't spinning you aren't earning. Taking a truck apart takes experience i dont have.

    Down towards Chicago there are some specialty automotive electrical shops that program ecms, delete diesels and diagnose electrical issues on mostly imports that most American shops are ill equipped to handle. Anything like that around where you live?

    Just to give you an idea of how nasty tap, shorts, opens or something going to ground when it shouldn't can be, The phone company used a device called a sidekick ($6g) hooked up to a generator on our trucks to apply amps/voltage on that gauge wire at an estimated number of feet in the hopes of bridging that open. None of that mattered when digitization happened. Running new wire was often the ONLY solution.

    Gets expensive quick though when that wire is buried in a tractor you have to partially disassemble/reassemble or goes under a 6 line highway.
     
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  10. TCF

    TCF Light Load Member

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    Oh... I could take it apart not problem and probably put at least 60% back together too...
    Issue is once electricity is involved I'm a 90s Mike judge character that will stare at you mute...... Don't know why.... Always been that way..

    I know 1 electrician around here.... And he's always weeks or months behind.....

    You have any good shop recommendations? Let me know.

    I'm near Bedford Park and the place I work... Always behind and just lost a guy today.
    Other one I use... Always behind..

    And as far as specialty ####.... Yeah.... I just know Raul.... And he's always backed up...

    Like you said... I need to be rolling to be earning and work is already hard to come by because it's so #### slow and the government still keeps saying we need more trucks..
    Not more dock workers.... Forklift operators.... Competent drivers.... Just more drivers..... #### the fact everyone is struggling....
     
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  11. Phoenix Heavy Haul

    Phoenix Heavy Haul Medium Load Member

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    It’s likely that the pins in the trailer connection have slightly collapsed and need to be spread out.
    This is very common on RGNs when your hooking and unhooking multiple times a day etc.
    If you get another chassis that the brake lights aren’t working or dim take a small flat blade screwdriver and stick it in the end of each pin and it will slightly spread it back out so it makes good connection again.
    See the slit in the end of the pins in photo. 333B4808-E698-4DEC-A2DA-A37E2CA6B25B.png
     
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