In the Final Fantasy XV gameplay, the Dynamo is a very important item because you use it to upgrade your Bio Blaster. In order to acquire this item, you need to complete the Bio Blaster quest called "A Better Bioblaster." After completing this, Cid will be able to make the necessary upgrade. Here's a Final Fantasy XV guide to find the Dynamo.
There are actually two places where you can find the Dynamo. The first one is in a warehouse and the second one is in Greyshire Glacial Grotto. To get the first Dynamo, you have to do the King's Struggle quest in Chapter 13. The warehouse is near the activation of the central elevator.
In order to locate that, go to the lower level of the warehouse. Once you reach it, head to the north where you can find canister racks. Search the canister racks to find a stair case hidden in a dark section of the room. Climb that until you reach the platform where the Dynamo is lying awaiting for you.
The next Dynamo is in the Greyshore Glacial Grotto which can be found on the North West part of the map. Specifically, it is inside the cave found behind a waterfall. In order to reach the waterfall, you need to travel to the West of Coernix Bypass and South West of the Burbost Souvenir Emporium. There's only one waterfall there so you cannot miss it.
Go to the entrance of the dungeon and follow the river. Keep on walking until you see an area with the treasure spot. The Dynamo is in that exact right spot but it's not as easy to obtain as the first one. You need to defeat a Level 50 giant snake first before you can get your hands on the Dynamo. Use the right strategy to overpower it and get the Dynamo for yourself.
Let us know if this Final Fantasy XV guide is helpful to you.
