Vehicles electronics systems and welding...Have i been just lucky many many times?

[snowbird]

Last week i welded on some equipment i just installed on a F_250 super duty 2015 (YES 2015) and had no second thought about it, and no problem either.

This morning i remembered things about battery isolators and other precautions, also heard the stories of nightmares about totaling ecm etc..

Just read that 2008 thread here : http://www.millerwelds.com/resources...ng-on-my-truck

Still not convinced about all these precautions.

Common sense such as a good clean work clamp close to the weld seems to be enough for me. Thinking about service trucks that have welding tables attached to the bed, do they disconnect battery?

Who has first hand experience with that?

Are there some fancier welding process ( hf. ac balance, pulse etc...) that have higher risks to induce damages to ecu etc...?

[eecervantes83]

From my experience. An electrical current always find the path of lease resistance. I don't disconnect my batteries either if I'm in the other end of the truck with the ground close to the weld area. But I always disconnect any customers battery. Just in case..

[snowbird]

thank's guys , 66+ views and only 2 opinions

ecervantes who disconnects (chicken! ???)

and me who does'nt...(idiot! ???)

[WillieB]

Welder voltage would be destructive to electronic equipment. Therefore don't connect your ground clamp to an ECM, then lay your work on it to weld. Generally a ground clamp connected to the work piece should mean nearly no voltage through the electronics.

[Welder99]

Welding and grounding

I've been welding for 34 yrs now and with the newer equipment out there with a lot of electronics it makes you wonder. I've done both unhooked the batteries sometimes and sometimes not. I have one customer with a ken worth dump truck that always unhook his batteries before I show up with the rig. One place I worked at required we double ground.we had a piece of weld cable 5 ft in length with a ground clamp on both ends, we attached the ground from the machine next to where we were welding and the double went right next to that ground and the other ex drove a ground rod in the ground and attached the other one to it. One thing that does come to mind is tig welding. High freq. will do strange things to electronics. So The best way today is to take the extra time to protect the electronics. Might be the difference of making money or losing your butt.
Happy Welding

[walker]

I haven't disconnected yet, and no troubles. Clean, shiny ground close to the work.

[Meltedmetal]

There are too many variables to give a definitive answer. There are likely scenarios where disconnecting the ground is worse than leaving it connected since you can't disconnect all the grounds in the vehicle. Not having a place to dissipate transients can be bad. A disconnected ground will probably protect the battery and maybe in most cases parts of the charging system but the ECM I'm not so sure. It might be more important to keep your leads away from the ECM and as much related wiring as possible. I wouldn't wrap my leads around the ECM to make an extra choke for instance. Disconnecting and removing the ECM might be safer but the potential for damage in handling increases and even finding them in some vehicles can be a challenge. Probably the best place to seek advice is the manufacturer of each individual vehicle. I still can't wrap my head around how boosting a Trailblazer burn out the circuit boards. I believe it does, I just don't see why.---Meltedmetal

[dandeman]

Welding and Inadvertent firing of air bag systems

I have the factory service and body collision repair manuals for several Toyota vehicles... Their guidance for on vehicle welding, in addition to the clamp as close to work and to know the welding current path, is also concerned about inadvertent firing of the air bags and seat belt tensioners..

Toyota air bag systems (unlike certain GM models as we have learned) have an auxiliary energy storage system that can fire the airbags for up to 90 seconds after battery power has been lost and independent of ignition switch setting.. This function is there as in the early phase of a collision, or 2 strike collision, the battery/wiring can be destroyed, yet the air bags still have power to fire.

Therefore their guidance is to disconnect the battery and wait 90 seconds before performing any on vehicle welding.

[gnforge]

Vehicles electronics systems and welding...Have i been just lucky many many times?

Also welded many years, a lot of different equipment. Within last couple months welded on Vac. Truck and directional drill. Both have heavy electronics. Did disconnect battery's but felt that never eliminated risk. I've always thought bare metal, good ground, close to work and kept ground on main welding metal between weld & electronics. Also always started arc on ground side of metal when tacking & starting weld.
Never thought of double ground. That is good idea. Maybe double ground both sides of weld area in high risk cases??

[snowbird]

Now the air bags :s...geee. we're walking on thin ice over a mine field!

I plan to experiment on a car to be taken out to scrap, will try to blow everything that i can and post pics. first by welding with proper procedure and even with engine running but no disconnecting.

Do you have suggestions for worse work clamp position ie. from muffler to weld on a fender, to battery ground lug, to remove battery and clamp the+ lug, i plan to mig stick and tig hf.

It would be nice to hear from guys that had PERSONAL EXPERIENCE of any kind of incidents involving welding and current damage to systems.

Hey cops! forget the spike strips, get a welder!

[Old Skool]

How long does it take to remove the battery cables, couple of minutes? If there's the slightest possibility of screwing something up why take a chance.

[Meltedmetal]

Never thought of double ground. That is good idea. Maybe double ground both sides of weld area in high risk cases??

I'm not so sure it always is a good idea. By adding more grounds you could increase the possible paths for current that otherwise wouldn't exist. As in from anywhere on the vehicle to ground. If you were welding with an engine powered weld that is not connected to earth ground the only path to complete the circuit is via the work cable. If you were to add more grounds and are using a grounded welder like one plugged into your shop power you will have created multiple paths. No? It might be an idea for person safety but not for electronic safety.---Meltedmetal

[Meltedmetal]

I have the factory service and body collision repair manuals for several Toyota vehicles... Their guidance for on vehicle welding, in addition to the clamp as close to work and to know the welding current path, is also concerned about inadvertent firing of the air bags and seat belt tensioners..

Toyota air bag systems (unlike certain GM models as we have learned) have an auxiliary energy storage system that can fire the airbags for up to 90 seconds after battery power has been lost and independent of ignition switch setting.. This function is there as in the early phase of a collision, or 2 strike collision, the battery/wiring can be destroyed, yet the air bags still have power to fire.

Therefore their guidance is to disconnect the battery and wait 90 seconds before performing any on vehicle welding.

That's a good point I hadn't thought about the air bags. I would guess even disconnected if you were to burn though a wire on the air bag system you could fire the air bags too.---Meltedmetal

[bigtow30t]

I started off my working career as a tow truck driver. I have blown a few abs computers by hooking the ground cable to the master cylinder. But now I weld on semis and never hurt the ecm.

[old jupiter]

dandeman, do you have an autobody repair shop? Tell 'em what a typical repair bill is for damage done by an airbag going off. In my ignorance, I supposed that the airbag just blew out and protected the driver, with no other consequence. That was before my dad's idiot second-wife ran their three-year-old Focus into a pole at low speed, discharging the airbag. Minimal damage from the pole, but the insurer "totaled" the car due mostly to the effects of the airbag.

A 1/2" end-wrench, possibly a screwdriver, and two minutes time or less disconnects the battery clamp . . . (all my own vehicles get the quick-disconnect battery clamp with the big knob on top).