I need to do some stick welding on the frame, 1997 4 Runner,the top rear shock absorber bushing hole is enlarged on one side, allowing the shock rod moving around, my question from you experts is that should I disconnect the battery, is there any danger of welding damaging the car electronics, do you have any better solution to this problem, thanks

Welds on several areas of my 4Runner with the battery connected, no problems here.

Mike

I'm surprised at that. I thought welding with a connected battery was a major no-no. <img src="/forums/images/graemlins/confused.gif" alt="" /> Glad to know it can be done!

-S

It can be done, the problem is in the ECU if your truck has one and can damage it (on some vehicles) it's just a rule of thumb so to speak to disconnect it.

I've been successful both ways.

HTH

it can be done, but it's risky.
the trick for welding on a vehicle is to keep the workpiece clamp as close as practical to the weld area. you want to limit the real estate the current has to cross to get from the electrode to the clamp. if it's too long, some of the current can get lost on the way and find other ways to ground. that's how it kills things on the way like computers.

It only takes 2 minutes to disconnect the battery. Isn't it worth the peace of mind to disconnect it?

I should refine my post.

Yeah, for the minute or two it takes to remove the battery cables, it is indeed cheap insurance. So is grounding as close to your work as possible. Maybe it's dumb luck or the robust quality of the Toyota electronics, but I haven't fried anything by welding on my frame without removing the battery cables.

As a side note, pretty much out of habit I remove the cables whenever I'm doing maintenance. Something ingrained eons ago when being taught to spin wrenches.

Mike

You are absolutely right about that it only take a second to discount the battery, but I bought this rig used and if I discount the battery the radio is going to die and I don't know the code to reset it, yes a trip to dealer, but generally my question was about cautions that should be exersized before welding on car. I got great hints from you, Thank you all.

If it's a factory radio on a 97 I don't think you have to worry about a code. My 98 didn't have any codes and I disconnected my battery many times.

I have the Toyota collision repair manual and it definitely warns to disconnect the battery before welding on the vehicle.. In short the concerns stated are possible damage to vehicle electronics or the possibility of discharging an airbag.. Given that it is so easy to do, it would be taking unnecessary (even if remote) risks to not disconnect first.

btw they specificly say disconnect the battery and wait a minimum of 90 secs for the airbag secondary energy supply to discharge before doing any welding. Apparently Toyota airbags have large capacitors in them (or in the control unit) with enough stored energy to still fire the airbag if even if the power connection to the battery got ripped away in the early stages of a collision.

While it can be done w/o damage occuring, it's kind of like saying I had a thunderstorm come through the area, nothing was damaged by the lightning strikes, therefore I don't need lightning protection on my equipment.. Sooner or later it just might bite. <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/zombie.gif" alt="" />

The above comments about putting the grounding electrode as close to the work as possible is key..

As stated, the concern would be the very strong magnetic fields generated by the welding current path coupling into any adjacent wiring or.. if really dumb about where you put the grounding electrode e.g. on frame and then welding on body metal or vice versa, you could inadvertently pull the welding current through the ground wiring (which is not that robust anyway).