As is always the case in Arc Raiders, finding all the random bits and bobs that you thought were completely useless until you suddenly need them is a right pain in the arse. I'm looking at you, humidifiers and toasters. The light bulbs that you need for the third phase of the Expedition Project are no different.
Light bulbs are annoyingly hard to find if you're just wandering around Electrical areas hoping they'll turn up in droves in containers: they won't, and you need to donate five light bulbs to tick off the third phase. Luckily, I've found two cars, both on Dam Battlegrounds, that almost always contain at least one light bulb, meaning you can complete this step in just a few runs.
Where to find light bulbs in Arc Raiders
The best places to find light bulbs are the two cars on the south side of the Electrical Substation and next to the extraction lift at Generator Hall on Dam Battlegrounds. You need to breach and search the hood of the cars to find the bulbs, just like rusted gears (which you'll need to level up your Gunsmith if you haven't already).
More specifically, the car at the Electrical Substation is between the broken wire fence and the facility itself on the south side. If you're unsure where the Electrical Substation is, it's a small area in the south of the Dam Battlegrounds map. Meanwhile, the car on the surface of Generator Hall is just a few paces southeast of the extraction lift, near abandoned buses, at the north end of Dam Battlegrounds.
I'm not entirely sure why, but these two cars in particular have a weirdly high chance of containing light bulbs. In the testing I did, I almost always came out of the match with at least one, if not two bulbs, so it'll likely only take you four or five runs to gather what you need. It's a great source for this item; the only drawback is that these two locations are basically opposite ends of the map, so be prepared for a marathon.
