Terraform - create list based on resource count query returned no results

I’m trying to create dynamically create a list of instance ids, to assign it to the loadbalancer. Based in this [question][1] I found I can do it using data "aws_instances"
Unfortunately I’m getting this error

Error: Your query returned no results. Please change your search criteria and try again.

This is the way I create my EC2 resources

resource "aws_instance" "one" {
  instance_type = "${var.lc_instance_type}"
  ami           = "${var.dev_ami}"
  count         = "${var.instance_count}"
  tags = {
    Name = "${var.name_prefix}-id

And this is the way I’m using the data aws_instance and how I plant to use it in the EB resource

data "aws_instances" "read-ec2" {
  instance_tags= {
    Name = "${var.name_prefix}-id"

resource "aws_elb" "loadbalancer" {
  instances = ["${data.aws_instances.read-ec2.ids}"]

  listener {

Not sure if I’m using properly the instance_tags option.