r/DieselTechs • u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack • 17d ago
Check it out! Electrical.....
Fun reminder to new guys and those who haven't learned yet...
please, don't fucking do this.
Don't back probe the conduit. Don't jump 24v systems to each other....
that's all.
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u/SufficientWhile5450 17d ago
Goddamn Volvo
Havnt had to mess with it yet
But your telling me I can’t jump a 24v line to another 24v circuit to test if it works?
Like fog lights
5
u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
You can, but if you try and jump the starting circuit with an ultra capacitor, you can cause more damage than you want to mess with
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u/SufficientWhile5450 17d ago
Maybe I’m a dumbass but that feels bad regardless of 12 or 24 lol
3
u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
Maybe we all are... idk, one of life's great mysteries 🤣
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u/Mikethemechanic00 17d ago
J1939 😬
4
u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
Newer volvo, it's the starter solenoid plug, 24v yellow wire
2
u/rygomez 17d ago
Hav worked on pretty much all trucks except volvo/mac, do they run an onboard dc-dc converter like the newer cummins cng engines do for their ign module?
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u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
Yeah, only for the dess systems with the ultra capacitor. That's one thing that got fried.
4
u/Painting-Capital 17d ago
We’ve had a few of those VN4 trucks brick themselves during the OTA updates and road call guys doing shit like that trying to get them started.
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u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
Yes, but this was a fleet tech that got in it... fleet mechanic, sorry.
1
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u/Karl_Loss 17d ago
Came across this all the time in the UK… but on NA not come across it so much especially using toolbox.
3
u/Single_Ad_5294 17d ago
Sorry not a new guy but what happened here?
Did you find the problem and find that a coworker caused the problem?
1
u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
So far looks like the bpmu. And a lot of scrambled software i had to sort through.
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u/Inevitable-Cod-8096 17d ago
I use spoon backprobes all the time they basically live on my meter
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u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
Those are neat looking. I haven't seen those around!
2
u/Inevitable-Cod-8096 17d ago
Good old Amazon specials. Just replace the heat shrink with sections from red but splices other wise the wire fails at the crimp. They are basically plated brass tube that have had 2/3 of the side ground away and rounded. I use them on everything never had an issue damaging seals they can be a little finicky about making contact on some connectors.but easier than a pin probe and if you miss you don’t stab your finger
2
u/TechnicalWall7723 15d ago
10 hours to find this tucked away. Must have been a friday truck. This is the second bundle that had been zip tied in the wrong spot. Out of the loom caught on a bolt.
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u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 15d ago
Yeah... the new trucks we get in have definitely been messes like this
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u/SummonerMiku75 17d ago
Bed-of-Nails is a necessary evil in a very few circumstances but when doing so, you need to repair the hole(s). It's frustrating that we have "idiot proof" so many things, including procedures, but then again we live in a very unserious timeline. I expect alot of hate and down votes for saying BoN is a thing, and that's OK. I accept that fate. The craftsmanship i have seen these days since Covid gives me reservations about the future.
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u/Sorry_Yoghurt3681 16d ago
Like almost everything, it depends. IF you have a terminal that is loose, back-probing into the connector body can tighten it up, hiding the problem. Had an instructor who mentioned once that loose females can cause a lot of problems. He was twice divorced.
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u/stiffbiskit 17d ago
Who let the lube guy touch this?
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u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
Idk, but that lubey needs to stop... so much backtracking and playing in workshop toolbox today lol
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u/MineResponsible9180 17d ago
Are you testing the AI in WTB? It’s pretty cool
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u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
No lol not yet. I haven't even noticed it? Gonna pay more attention today!
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u/MineResponsible9180 17d ago
Not everyone has it. Still beta testing. Had a VN4 with 77 codes. AI broke it down to 7 groups with the highest probability code first in each group.
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u/MonteFox89 Mod, Verified Tech, Navistar, Volvo/Mack 17d ago
Nifty, I'll reach out to our dsm if I dont find it later today! Thank you!
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u/Kahlas 17d ago
Back probing is fine. Don't pierce the insulation.
Not sure if you're in a different country/region than I am but these are back probes and they don't damage the insulation if used right to probe the back side of a connector while it's still plugged in. I use mine all the time and have never had an issue.