Automation to turn on fan when Temperature is lower than Thermostat target

Configuration
1

I’m trying to automate my Garage Attic fan.
I have an ESPhome thermostat running hvac in the garage, a switchbot as external temp sensor, and a shelly v1 switching the attic fan.

I’d like to turn on the fan when external temp is below thermostat target temperature, and off when above (if I can do one, the other is essentially duplicate)
I setup what I thought would work, but it didn’t fire when I expected.

Here is my Yaml for Fan on.

alias: testAtticFanOn
description: ""
trigger:
  - platform: template
    value_template: >-
      {{ (state_attr('climate.garage_thermostat', 'target_temperature_high') |
      float) >= (state('sensor.indoor_outdoor_meter_0669') | float) }}
    for:
      hours: 0
      minutes: 1
      seconds: 0
condition: []
action:
  - type: turn_on
    device_id: 7058023a2087827800342a43ad157d92
    entity_id: 5a8484bba340e3796dcf6d5d7c59aa53
    domain: switch
mode: single

is there an easy way to test whether it’s my trigger, or whether my units are wrong?
I’m quite new at automations and honestly shite at programming.

2

Go to Developer Tools → Template to test yout trigger template.

Go to developer Tools → States to make sure you have the correct entity_ids and attribute.

Units?

Also regarding your action: Why and how to avoid device_ids in automations and scripts

3

This is EXACTLY the help I needed!!
Thanks. This community is awesome.

As for units. I guess I meant type (ie float/int/string/etc)