DIM oem LED taillight (T4R)

Ok so I posted this in the 4runner section but have yet to get a single reply, since theres a lot more traffic here I will try my luck here. Taillights should be almost identical anyways. Just want to get it done by this weekend for her.

My wife's 07 T4R has a dim driver's side LED tail. Just saw this the other night as I was following her home from a night out. The light is just dim, brake light is dimmer than the passenger side as well. I can't find her owner's manual and wasn't sure if its the same as my '12 Taco lights. Had a little time last night after work to check it out and saw it was just wires and no bulb. I'm also thinking it could be a fuse, haven't checked it yet though.

I don't have experience with LEDs so I have no clue how they work. I usually search before I post but my damn phone won't let me type in the search box. Any help is greatly appreciated. Don't want her to go through the hassle of getting pulled over again.

 

Since both the tail and the brake lights are dim I would guess maybe it is a bad ground on that side. Could be something else but I would check the ground first.

 

It probably is a bad ground. I highly doubt it's a fuse. If a fuse was blown then the lights wouldn't be working at all. I don't think that this is a common problem, it's a first that I've heard of it.

 

Thanks guys. I almost forgot as well that that light was replaced not too long ago due to her hitting a mailbox. I will definitely check the ground. Figured it wasn't a common problem since the search bar netted me nothing close to what I was looking for.