torqueman2002
Well-known member
Your dandy example sounds more like a lightning stike.
Did someone here say that was due to welding?
I missed it.
I would not think welding.
When welding on vehicle disconnect battery?
- Thread starter KMinAF
- Start date
Your dandy example sounds more like a lightning stike.
Did someone here say that was due to welding?
I missed it.
I would not think welding.
The only vehicle I welded on and didnt disconnect the battery burned out the alternator. Coincidence ??
At work ( GM Assembly plant ) whenever we had to do weld repairs on finished vehicles, the battery was disconnected and the PCM removed from the vehicle.
At work ( GM Assembly plant ) whenever we had to do weld repairs on finished vehicles, the battery was disconnected and the PCM removed from the vehicle.
torqueman2002
Well-known member
Here's a bit more of the post for some context.
"...take all the 'engineeringeeze' and boil it down to where we all can fix these increasingly complex cars and trucks.
Heck, I discovered some cars (not trucks yet, GM anyway) can set history DTCs with the ignition off. ¡Ay, caramba!"
Not related to the exact topic, just saying how complicated today's cars/trucks are becomming. You can't fix today's vehicles with 10 year old skills/knowledge and some cases tools. You might not fix a 2006 car using 2005 service information.
Here's a bit more of the post for some context.
"The purpose of disconnecting the battery is to isolate the sensitive components from the electrical surges that seek to complete their path to neutral potential through a component, back through the battery positive and battery negative; not to protect the battery."
Sorry for the confusion, this is what I mean:
To be electrically neutral means no net electrical charge.
I hope this clears up some questions.
torqueman2002
Well-known member
OK, I'm taking a break from answering questions.
Now it's your turn sberry.
Now it's your turn sberry.
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rodknocker
Well-known member
This argument takes more time than it does to disconnect the battery, or PCM, so why not do it. If out of the blue, your computer **** the bed in your car thats out of warranty, and the mechanic came up to you and said if you had taken 3 minutes out of your day to help your vehicle, and this would not have happened, all of us would have taken the 3 minutes, so why is this thread still going on?
torqueman2002
Well-known member
Thank you, I beleive it's time for me to leave.
I'm tired, anyway.
rodknocker - I miss 'Rot N Fester'; lived in the 19th Ward until '91. Go RIT!
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There are many ways a "high voltage discharge" can - and will- destroy sensitive circuits in a car without any current flowing through the battery. Thus, disconnecting the negative terminal makes little or no difference. An example: If I roll around inside a car and my body gets charged (static) - then I go playing with PCM connections a discharge from my fingertips to ground (chassis/body/frame) via PCM sensor input can destroy said input circuit. The battery might be a path for the discharge but I find the ground harness much more likely candidate.Sorry, but the other leg of the circuit is the positive to the battery, so even a component (ECM, BCM, ...) connected to chassis ground will be isolated in the sense there is not a complete circuit through the battery.
The purpose of disconnecting the battery is to isolate the sensitive components from the electrical surges that seek to complete their path to neutral potential through a component, back through the battery positive and battery negative; not to protect the battery.
Every required step in a service procedure contributes to the labor operation code and time paid for that code. The manufactures do not pay for unnecessary steps. In fact, there is a reward (Suggestion Program) for reducing any unnecessary steps/procedures in labor operation codes.
What reason do you propose the manufactures have for requiring battery disconnect?
I remember seeing requirements from manufactures to disconnect the battery AND connecting the battery leads together using a clam or bolt while welding. * I am not sure but if memory serves me these were Komatsu and MAN. Unfortunately I cannot offer positive proof cause I no longer have access to said service manuals to look it up. Now why would they want to connect the battery leads together if disconnecting the negative lead does the trick - as in
*
This is actually considered "best practice" in few shops around here when welding in cars, trucks, heavy machinery, construction machines e.t.c.
sberry
Banned
You can over think every potential possibility too, I forget what the numerical potential to get struck by lightening is, sure its there and less than the odds of getting it in a traffic accident too, you can easily prove you are smarter than I am too, no contest , get no argument from me there but I could be convinced had I ever seen it happen, know of a reliable account of a problem, we see testimony from muffler guys here, welding rigs on new trucks at how many? How many cycles a day sometimes these are welded on, try to hook something wrong with a car weeks later is likely pure speculation at best, ain't no secret cars give some of the smartest people fits that have never been welded on, lots of those in the shop for gremlins, thousands of those.
95 % of that is luck of the draw ****, some little gizmo takes a dump, who knows wtf went wrong with it. How you gonna equate that some guy welded on it six weeks ago without having disconnecting a battery?
95 % of that is luck of the draw ****, some little gizmo takes a dump, who knows wtf went wrong with it. How you gonna equate that some guy welded on it six weeks ago without having disconnecting a battery?
torqueman2002
Well-known member
torqueman2002
Well-known member
Sorry, just having a talk. Not what I am trying to do, just offering my experience.
I will shut up now, seems I've offended you. Sorry.
sberry
Banned
You are not offending me and I got a great respect for engineering and education and I would be very interested in reading some real evidence vs technical speculation at best. 500K education is good especially if added with 5$ logic, after long history of doing this, after long history of others doing it I don't see any evidence and although I didn't read all the links some dipstick with a buzzer hooked to the battery as a grounding point doesn't count.
People do all kinds of things to damage cars that are real, hooking unhooking batteries has caused all kinds of problems, poke everything with a test light, the scotch lok connector had done its fair share as has the installation of all kinds of after market equipment, many poor service practices, people put **** in gas tanks that shouldn't be there, simple human error causes thousands if incidents, happens in my own shop, cars with mystery problems are all over the country, all these threads speculative, I am sure it has happened somewhere at some time but its not one of life's great risks, so small there is no real statistical evidence.
Here is another anecdote that comes to mind,,, I know several people that will not fly on a commercial airliner but don't think twice about throwing a leg and the wife on a Harley and driving on public hi way.
My adilac, never been welded on, lots of flassing lights, my work truck, welded on hundreds of times no problem. Hard to make a cause effect to most of these problems. Been at this a long time, never seen it. I suspect most issues were there before the arc was ever struck, the mind tries to connect the dots.
People do all kinds of things to damage cars that are real, hooking unhooking batteries has caused all kinds of problems, poke everything with a test light, the scotch lok connector had done its fair share as has the installation of all kinds of after market equipment, many poor service practices, people put **** in gas tanks that shouldn't be there, simple human error causes thousands if incidents, happens in my own shop, cars with mystery problems are all over the country, all these threads speculative, I am sure it has happened somewhere at some time but its not one of life's great risks, so small there is no real statistical evidence.
Here is another anecdote that comes to mind,,, I know several people that will not fly on a commercial airliner but don't think twice about throwing a leg and the wife on a Harley and driving on public hi way.
My adilac, never been welded on, lots of flassing lights, my work truck, welded on hundreds of times no problem. Hard to make a cause effect to most of these problems. Been at this a long time, never seen it. I suspect most issues were there before the arc was ever struck, the mind tries to connect the dots.
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GirlnAgarage
Well-known member
Oh my gosh....unsubscribe.
Really people. Disconnect if you want. Don't if you don't wanna.
Really people. Disconnect if you want. Don't if you don't wanna.
$1500? You working on a Bugati?
sberry
Banned
You are right, free country, and now that we have this vast personal experience from the one time and deep knowledge gained from it its settled and we can all go back to bed.
I went to tech school in 1970 and was taught at that time to disconnect the battery and not to connect the current path across bearings. So this discussion predates computers by a long time. I have also blown up a battery connecting up jumper cables correctly. The spark set off the gas. These stories come from some problem in the past. I'm sure if you set up the correct situation you can repeat a problem.
lg
no neat sig line
lg
no neat sig line
Lotek
Well-known member
Torqueman, what do you think about surge protectors?
Some at our bodyshop use them, others just disconnect the cables, I have had to replace and program an ecm for them, verified that he had the cables hooked up, so it does happen, mgr wasn't happy, made it a rule.
Some at our bodyshop use them, others just disconnect the cables, I have had to replace and program an ecm for them, verified that he had the cables hooked up, so it does happen, mgr wasn't happy, made it a rule.
wreckercologist
Well-known member
I'm certainly not torqueman, but since you asked.......
I use 'em at work every single day. I weld on trucks every single day without disconnecting the batteries. Never had a problem in 13 years. That said, everyone can use their own judgement on whether or not to use this item or just disconnect the battery.
By the way, if bought off the Mac truck and branded Mac, those surge protectors haev a lifetime warranty. I've had a few replaced.
Sparkfarmer
Well-known member
As devils advocate, If the connection between welder ground and welder anode are poor. The batteries low internal impedance could allow current flow from the anode of welder, through the batteries, then through electronics to welder ground, frying the electronics.
I wouldn't worry about personally though.
pcmeiners
Well-known member
The only issue I can see with welding on a vehicle is EMF pulses, not likely but technically possible for damage to occur. Removing the postive battery lead and grounding it might prevent EMF pulses from reaching some components, if welding is within the engine compartment. I would disconnect the EMC connectors.
Was on a oil barge which had a computer network on it, they had welders outside within 3-6 feet of the computer wiring; gas driven welder, high current welding. The pulses from the welding did not damage anything due to wire shielding ( cat 5 wire twist negates interference/EMP pickup) but no one could use their machines as the monitors were completely unreadable during any welding particularly during arc striking; during each arc strike the monitors would go black for a second, then come back to jumbled color.
Was on a oil barge which had a computer network on it, they had welders outside within 3-6 feet of the computer wiring; gas driven welder, high current welding. The pulses from the welding did not damage anything due to wire shielding ( cat 5 wire twist negates interference/EMP pickup) but no one could use their machines as the monitors were completely unreadable during any welding particularly during arc striking; during each arc strike the monitors would go black for a second, then come back to jumbled color.
This welding will be on the rear axle shock mount.
Neve hurst to disconnect. Just my dual battery system really has everything tucked and rather recessed. However, a few knuckle rubbing seconds is better than a new computer or batter or whatever.
Neve hurst to disconnect. Just my dual battery system really has everything tucked and rather recessed. However, a few knuckle rubbing seconds is better than a new computer or batter or whatever.
TauntDevil
Well-known member
A lot of posts on here go from battery to pcm when there are fuses and relays between the battery and pcm (ecu, etc). I have never disconnected the battery but I will always remove the ECU or at least disconnect it as some ground through their cases and that could be at risk but the battery itself really isn't all that important. Just my two cents though from being at a fabrication shop for a few years.
stephen4785
Well-known member
I worked at Midas for 6-7 months when I was younger. I probably welded on exhaust systems 4-5 times a day every day. I never disconnected a battery or did anything other then start welding. Iv also welded up countless things on vehicles including a bunch of offroad rigs that had tons of cash in them and still never disconnected anything and didnt have any problems.
sberry
Banned
This would be good logic if it actually did something.
Flivver250
Well-known member
You can use an anti-zap clipped to the battery. Mac tool sold them.
http://www.amazon.com/dp/B000FN2T06/?tag=atomicindus08-20
http://www.amazon.com/dp/B000FN2T06/?tag=atomicindus08-20
Joe69
Well-known member
I've been chucking parts up in the vise on the back bumper of my service truck, and welding them up for 20 years. Never a single problem. Make sure you have a paint and rust free ground, and you'll be fine. I've had everything from a '93 F450, to the 2015 Freightliner M2 I now have. Plenty of electronics, but not one problem caused from welding.
Joe
Joe
Engineering
New member
- Joined
- Oct 3, 2014
- Messages
- 3
You can easily 'splode a battery with a welder. Ask me how I know...
Although, it's true that "most" of the electrical current will take the path of least resistance. However the current can run through the battery connections especially if the battery's electrical path is between the stinger and ground clamp. A car battery also has an internal resistance which plays into it. At this point, the lecture continues but gets into "engineering" talk.
Short story:
Safety first...
This is the same principle of disconnecting the battery while turning wrenches on your vehicle.
Although, it's true that "most" of the electrical current will take the path of least resistance. However the current can run through the battery connections especially if the battery's electrical path is between the stinger and ground clamp. A car battery also has an internal resistance which plays into it. At this point, the lecture continues but gets into "engineering" talk.
Short story:
Safety first...
This is the same principle of disconnecting the battery while turning wrenches on your vehicle.
Welded on cars all the time with no issues until I was welding the exhaust on my 2008 Nitro. Of course project took longer than expected and when I was finished I pulled it out of the shop only to find out I had no lights of any kind. Googled it and found a service bulletin to reset the TIPM. I now unplug the battery......
sberry
Banned
Feel free to edumacate uz.
bubinga
Well-known member
Ever since you welded my muffler, my LR tire keeps loosing air .
Superbec
Well-known member
this!
I welded tig&mig on many vehicles for years , no problems ever till recently one scooter with a painted frame and bad massa connection ... I fried the ecu and coil !
I couldn't get the massa cable close to the weld area so I put it on the engine , assumed there's a connection between them .. WRONG the only connection was thru the coil ground to chassis that someone modified to be the single ground to chassis on the bike ..
With bikes/scooter I take the battery out and charge first thing I do, saves a lot of trouble but I think this time was not exactly helping.
joe49
Well-known member
SO how do you know? Feel free to use some engineering talk.
lakeroadster
Well-known member
Night Of The Living Thread....
The thread that keeps coming back to life....
The thread that keeps coming back to life....
Whiskeybadger
Member
- Joined
- Jun 25, 2014
- Messages
- 15
I welded a bumper on my Durango and it fixed the radio...Not sure what that means
^ ^ ^ Think that GM must have done ALL the welding on Pontiacs with wiring complete and battery installed.
They had more electrical gremlins than any Big 3 that I can remember. Now the British have the all-time record for electrical gremlins of all vehicles !!
They had more electrical gremlins than any Big 3 that I can remember. Now the British have the all-time record for electrical gremlins of all vehicles !!
