# Pullup, Pulldown, 1M - how to trigger the AC

**URL:** <https://community.ecumaster.com/t/pullup-pulldown-1m-how-to-trigger-the-ac/5246>\
**Category:** EMU BLACK / CLASSIC\
**Created:** [February 17, 2026, 7:50am UTC](https://community.ecumaster.com/t/pullup-pulldown-1m-how-to-trigger-the-ac/5246 "2026-02-17T07:50:58Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![bgmenchaca](https://dub1.discourse-cdn.com/flex013/user_avatar/community.ecumaster.com/bgmenchaca/32/107_2.png) [@bgmenchaca](https://community.ecumaster.com/u/bgmenchaca)\
**Post date:** [February 17, 2026, 7:50am UTC](https://community.ecumaster.com/t/pullup-pulldown-1m-how-to-trigger-the-ac/5246/1 "2026-02-17T07:50:58Z")

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Hello,

Hoping for ideas (since I out of them)… with sensor setup at 1M pulldown when I switch on my AC the AC request circuit goes from 0v to ~2.2v, the challenge is its not enough voltage to trigger the ECU to engage the AC since it needs \>4v.

Not knowing any better… I experimented and set #4 to 4K7 Pullup, that bumped the voltage to ~4.6v and the AC worked! When I turn off the AC switch in the dash the AC cutch stays engaged because there is no change in the voltage… what to do?

Is there a combo setting between Sensor Setup and Activation Input, that will make this work?

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<div class="post-metadata">

**Author:** ![bgmenchaca](https://dub1.discourse-cdn.com/flex013/user_avatar/community.ecumaster.com/bgmenchaca/32/107_2.png) [@bgmenchaca](https://community.ecumaster.com/u/bgmenchaca)\
**Post date:** [February 17, 2026, 12:27pm UTC](https://community.ecumaster.com/t/pullup-pulldown-1m-how-to-trigger-the-ac/5246/2 "2026-02-17T12:27:39Z")

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I think I’ve figured it out… if I used a virtual input and selected the 1.5v (1500mV) as ‘on’ and point it to the analogue input then it would work.