# Wiring garage door sensor

**URL:** <https://boards.straightdope.com/t/wiring-garage-door-sensor/739727>\
**Category:** Factual Questions\
**Created:** [December 7, 2015, 6:43pm UTC](https://boards.straightdope.com/t/wiring-garage-door-sensor/739727 "2015-12-07T18:43:57Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![dauerbach](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@dauerbach](https://boards.straightdope.com/u/dauerbach)\
**Post date:** [December 7, 2015, 6:43pm UTC](https://boards.straightdope.com/t/wiring-garage-door-sensor/739727/1 "2015-12-07T18:43:57Z")

</div>

My garage door currently will only go down with constant pressure on the wall switch. There is no red light on the beam, but when I connect it to power unit directly I get a red light. From this I suspect the wiring itself is bad. But I have a wire pair going to the light, and a wire pair going to the sensor, but only one wire pair to connect to the the power unit itself. Where and how do these two sets of wires come together?

---

<div class="post-metadata">

**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\
**Post date:** [December 7, 2015, 10:44pm UTC](https://boards.straightdope.com/t/wiring-garage-door-sensor/739727/2 "2015-12-07T22:44:04Z")

</div>

Find the make and model of the unit - without at least that, it will be impossible to answer your question(s).  
Once you have that, google ‘make model install’ - there should be a copy on the manufacturer’s site.

Did this ever work without holding the button down? That is a biggie - if it used to work witho only one side wired, you have that answered.

---

<div class="post-metadata">

**Author:** ![dauerbach](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@dauerbach](https://boards.straightdope.com/u/dauerbach)\
**Post date:** [December 7, 2015, 11:21pm UTC](https://boards.straightdope.com/t/wiring-garage-door-sensor/739727/3 "2015-12-07T23:21:54Z")

</div>

Yes, if I hold the button down it will go down. It is definitely the wiring. Right now I have it working but not fixed. Need some wire, and then I can rewire the whole thing.