Welding on a vehicle/machine with electronics...

[Big Wave D]

What precautions, if any, should be taken?

Whether something on a modern vehicle or an implement still attached to the 3pt on one's tractor, what are the dos and don'ts of an on machine repair?

My 1991 Kubota L35 I believe to be a non-ecu motor, but I am wondering about screwing up any of the other parts of the electrical system. I have some repairs that I am needing to make to my rotary mower and it would facilitate and make them easier by simply leaving it on to do them.

Okay to do or asking for expensive repairs???

 

[ihuntbear]

should unhook the battery and keep the ground clap as close to where your welling as mush as possible

 

[GPintheMitten]

I also wonder about this. Looking forward to the answer.

 

[Big Wave D]

ihuntbear,
Thanks for your response.

Now that you have stated it again, I seem to vaguely remember hearing about the 'disconnect the battery' advice from somewhere before.

Getting the ground clamp close makes sense also. Try to give the shortest path possible.

 

[rjmack]

Getting the ground clamp close makes sense also. Try to give the shortest path possible.

yes, the idea being that the electricity gets to ground before it has a chance to go through any electronic devices.

you do need to make sure you have an nice clean contact to your ground clamp as well.

obviously, proximity to fuel tank/lines is always an issue.

 

[cdaigle430]

When I was a professional welder, I learned from experience to:

1) Seperate the part if you can, if not then;
2) Disconnect the battery
3) Disconnect the alternator-for some reason welding on a vehicle with the alternator connected can result in alternator death or worse damage to elsewhere.

 

[Big Wave D]

obviously, proximity to fuel tank/lines is always an issue.

WHAT???!!!!! Where's the fun in that... :confused2::confused2::confused2:


just kidding.


Always good to remind all of us about working safely and not taken unneeded chances.

 

[Big Wave D]

cdaigle430,
How many boo-boos did you experience before that hard knock lesson was learned?

 

[junkyard]

also the ground can arc accross bearings, so once again u need to have your ground as close as possible to the project

 

[Soundguy]

i do alot of welding on tractors, and have done some on vehicles, though not much.

I 'generally' remove the positive clamp of the battery.. but .. not always.. unly if I remember..

I ALWAYS put my ground clamp within inches of where I am welding, and assure a good clean connection by grinding on the frame a bit where the clamp goes.

don't seperate the ground clamp from the weld area thru pins and bushings or bearings, or steering components like tie rod ends or any moving joint.

In the couple of cases I have needed to weld in close proximity to an alternator, I bit the bullet and unhooked it... then welded.

i've -NEVER- lost a alternator, starter, genny, regulator, dash cluster, lamp, resistor, diode or capacitor, relay or solenoid, including ei modules and hour meters, or any other electro or electro mechanical parts that I know of, as a result of welding on a machine.. i fot plenty of machines.. and probably every one has had something welde don it.. or something attached to it had something welded on it.

for my big implements that are many hundred, or in some cases, many THOUSANDS of punds.. I simply couldn't unhook them for ease of movement or maeuvering, and thus they stayed married to the tractor for the welds. small implements get welded when not attached, if convienient.

When I made up a subframe for my TLB I scabbed togeter while adding the 'B' of the 'TLB', 80% of the frame fittment and welding was done with pieces instaleld on the tractor, IE.. fit frame and whatnot up then tack weld to make sure it fits, then weld up if all is good.

didn't pop any batteires or alternators.. etc.. and i burned a good box of rods on that project using my AC crackerbox.

all that said....your mileage may vary.

if you feel any hesitation about welding on something.. be safe.. unhook stuff.. etc..

soundguy

 

[cdaigle430]

twice, worked for a couple of companies that were all about time rather than proper procedure. Luckily it came out of their pocket not mine

 

[Big Wave D]

It seems that the best action to take is to remove implement from tractor and find a different way to raise mower.

Thanks to all for advice. :thumbsup: It will be heeded.

 

[Big Wave D]

twice, worked for a couple of companies that were all about time rather than proper procedure. Luckily it came out of their pocket not mine

That seems like a definite trend in the making and not a one time fluke.

Glad to hear that you weren't on the hook for their poor decisions.

 

[muddstopper]

We have some computerized equipment at work. Once the mechanic needed to do some welding on one piece. We always do the lockout tagout procedures and this includes turning of the battery masterswitch and locking with tag. The switch was off but not locked out while he was looking at the machine and when he got ready to weld, he turned the battery switch on and the proceeded with the lock and tag out. When he got done makeing the repairs, you guessed it, nothing would work. The welding shorted out a bunch of circuit boards, $10,000 worth. It was a very costly lesson. A few weeks later, the same mechanic had to weld on another piece of equipment that was parked right behind the first piece he had screwed up. This is railroad equipment setting on metal rails. The first piece of equipment was actualy running when he struck an arc on the second piece, Bam! the first peice shuts off and another $10grand down the drain. Lots of mad folks when I had to call it in.

On pieces of Equipment with the new JD engines, we unplug the ECM before the welding leads are dropped off the truck. Welders pop them like popcorn.

I vote for unhooking the battery when welding and if its a new model with electronics, unplug the control module too if you can.

 

[JB4310]

When I was a professional welder, I learned from experience to:

1) Seperate the part if you can, if not then;
2) Disconnect the battery
3) Disconnect the alternator-for some reason welding on a vehicle with the alternator connected can result in alternator death or worse damage to elsewhere.

HMM!

Normally when this topic comes up I chime in that I do it all the time, weld on trucks and tractors with out isolating the electrical components. With no apparent problems.

But maybe I have to rethink that position, I did weld on my brand new trucks trailer hitch, with out disconnecting the battery, that was in 08, but this year the alternator went and when they replaced the alternator, they found out the ECM was bad too. Now that was 3 years ago, but the truck only has 26,000 miles on it so that is way to early for either of those problems to have occurred.

Luckily I had 3 weeks left on an extended service contract, cause the ECM was $1,800. alone just for the part. Didn't really associate this with the welding, but since you mentioned the alternator, it made me think.
I wonder if there could be such a delayed reaction ???

JB

 

[Soundguy]

that long? not very likely... should have been noticeable.. kinda like a fuse. works or don't.. immediately..

 

[Big Wave D]

muddstopper,

OUCH! What is the old adage, don't kill the messenger.

Twice in a row to the same poor guy. Would have thought he'd have been SO gun shy about doing any welding around that 1st machine. :ashamed:

 

[mjncad]

Besides the obvious of having a fire extinguisher nearby; I'll place a welding blanket over areas of the vehicle I don't want sparks to get at.

 

[Tiny Tym]

It depends!

The welding current has to flow through something, and that current produces a strong magnetic field. That magnetic field can couple energy into other circuits (similar to the way a transformer works) and, if you are unlucky, you might couple enough energy into an electronic circuit to destroy a semiconductor.

Whether the battery is connected or not has little to do with it. You can frazzle an electronic device with an EMP (electro-magnetic pulse) even if it is not turned on.

If you don't want to remove all the electronics, the best thing to do is keep the ground clamp as close as possible to the point where you are welding, and make sure it is really well connected to the metal. What you want to do is give the return current the easiest, and shortest, path back to the welder. If you are really finnicky, keep the ground lead and the electrode leads as close together as possible. You might even put them in a lazy twist if you can.

If the ground connection is poor, and you attach it at the opposite end of the vehicle from where you are welding, be prepared for trouble.

 

[Big Wave D]

Tiny Tym,
I like the lead twist idea. They use twisting of conductors inside Ethernet cable to eliminate cross talk. Certainly makes sense that it would work on a ramped up scale.