Welding on a car battery disconnected or not

[autosri]

Gunna be doing a bit of welding on the 14a and was wondering if I need to disconnect the battery or not

Welding in some harness plates at the back

Thanks

[ANDY black s13]

disconnect it and just to be sure unplug the alternator, I have seen even with battery off the alternator can fry inside and kill it

[autosri]

When you say unplug the alternator what exactly do you mean The actual output wire or the voltage sensing wire
sorry if it sounds like a dumb question I've not looked at the alt on this car and never done welding on a car it's always been stuff I've been able to remove and weld

[-ghost-]

I always just pop the battery out tho the amount of welding I've seen garages do with everything still connected not sure it makes any difference maybe the amps/amountvolts are too low.

[ANDY black s13]

When you say unplug the alternator what exactly do you mean The actual output wire or the voltage sensing wire
sorry if it sounds like a dumb question I've not looked at the alt on this car and never done welding on a car it's always been stuff I've been able to remove and weld

It may not be needed on our S bodies but I prefer the err on caution option and disconnect every thing on the alternator
I can't remember exactly which car it happened to and not sure how it happens tbh? possibly the earth getting power/reverse voltage?
,but I know it had a load of welding done,(it was a bodyshop) and the alternator dashlamp was on afterwards and it stunk like it had been fried
possibly it was a mk1 golf but after seeing it happen I go with remove wires from alternator and of course the battery

[Jonny Wilkinson]

There have been cases of fried ECUs on s13s through not disconnecting battery. I always disconnect when welding mine