Welding to frame Question (1 Viewer)

[Bigbeast]

I am about to weld on the frame of my 2001 4runner. Should I disconnect the computer from the wiring harness or leave it? I have read both on the internet. I will be using a stick welder if that matters. I already plan to disconnect the baterry cables.
Thanks in advance
Ken

 

[-Spike-]

IIRC removing BOTH battery cables is the correct procedure. Might I suggest that you post this in a Tech forum so as to get a better, more knowledgeable response? I doubt that those of us in Arizona know more than the rest of the country about welding.

-Spike

 

[Tools R Us]

Disconnecting the ECU is good insurance, but probably unnecessary, plus there are a bunch of ECUs in your truck. Disconnect the battery and make sure the welder ground clamp has a good connection as close as possible to the weld site.

 

[RUSH55]

From experience I've had welding on KW's and Pete's with ECM's, disconnecting one battery cable is sufficient, either P or N.

 

[goodtimes]

There is a chance of electronic damage if any of the circuits are grounded through the chassis (not likely in modern vehicles), and the positive terminal is connected. Basically, you have to create a difference in potential on both sides of the ECU/ECM/PCM/whatever....12v in the battery, and whatever voltage you are welding with on the chassis side. In order for this to happen, you are going to need either a very poorly placed ground (for your welder), and/or a very weak ground....the resistance from the electrode, through the ECU/ECM/PCM/whatever has to be less than the resistance from the electrode, through the frame and back to your welder via the ground cable....like I said....there is a chance. There is also a chance that I will win the lottery, keeping in mind that I don't buy tickets. Make sure you have a good ground close to your work zone, disconnect the + terminal, and you are pretty much eliminating the risk.

 

[RUSH55]

Goodtimes, elaborate. I'm gonna need to see pictures.

 

[goodtimes]

Pictures????

Simply put, electricity will always (ALWAYS) follow the path of least resistance. Make sure the path of least resistance leads directly back to your welder via it's ground cable.

 

[Bigbeast]

Thanks for the tips, I ended up disconnecting both battery cables and gounding the welder right next to the area to be welded. After I looked at all the ECUs, I decided that I did not want to disconnect the whole wiring harness. There are ECUs everywhere!!

Here are a couple pics, I had to make the front of the frame rail look like a Tacoma.

I had to cut of the factory bracket and weld on an end plate with attached nut.

 

[Tools R Us]

Looks great, what an improvement!

 

[goodtimes]

... gounding the welder right next to the area to be welded.

That is the most important thing right there.

 

[RUSH55]

Pics please......

Just joshin' ya!!