Welding and its effects on the charging circuit

Retrorod · Jul 19, 2014

I have a John Deere ride-on that cracked its mower deck bracket. Without thinking, I welded the thing, without disconnecting the battery connections.

The alternator does not charge (it may have been like this when I purchased it, but I do not think so).

I suspect that welding the mower deck as I have, I may have damaged the AC to DC regulator:thumbdown: . Does anyone agree? If so, where may I locate this device?

Thank you to any interested member that can put me on the right track. RR

Retrorod · Jul 19, 2014

It was remiss of me to leave out the mower details. It is a L110 John Deer with a 17.5hp Kohler engine. Thank you.

mikehaugen · Jul 20, 2014

Depends where you had the ground cable. I know they "say" you should disconnect the battery... but the weld current will tale the path of least resistance- directly from electrode to ground. I weld all of the time on industrial equipment with much more sensetive electronics and have never had a problem. Again, they "say" you should disconnect power, sometimes I do to be safe, but many times I forget... besides it only disconnects line voltage but does not open the path through the other electronics so I never saw much point.

Ed of all trades · Jul 20, 2014

I once welded a nut on a goose neck hitch in the bed of my truck. I put the ground clamp on the hitch and burnt out the electric oil gauge. Now I try to always pull the ground cable and keep it from any metal. "The path of least resistance" is not always the problem, 12V gauges and alternators are not able to take anything close to that kind of amps any where near them. I would assume that a repair service could repair it for you.

Gary Fowler · Jul 20, 2014

I have welded on all my tractors & my brother in laws without any issues. I always grind a clean spot and attach the ground directly to what I am welding. Never had any electronics go bad.
Your experience may not be the same as I have "heard" of things burning out from welding.

I would never weld on something that is just a few inches or even a foot from sensitive electronic components though. EM waves of energy from the magnetic field created around the weld might just fry a gauge or computer chip. I don't think removing the ground would help in that situation either.