How to Wire a Motion Activated Floodlight with an Insteon In-LineLinc Relay

This article explains how to re-wire a Heath® Zenith motion activated floodlight, model SL-5412, with an Insteon In-LineLinc Relay #2475S2 for automation of home lighting. This technique should work for most motion activated floodlights, for example the Heath Zenith Model # SL-5318.


The In-LineLinc Relay model #2475S2 with a Yellow Sense wire input for interfacing with the floodlight has been manufacturer discontinued. The current model In-LineLinc 2475SDB lacks the Sense wire that connects to the floodlight infrared motion sensor output so the floodlight turn On if it senses motion.

See the How to Wire an Insteon 2443-222 Micro Switch to a Motion Activated Floodlight for the new way to do this with the 2443-222. An alternate approach for basic lights is explained in Automate Exterior Lights with an Insteon Wireless Motion Sensor.

The benefits of an In-LineLinc On/Off relay in a floodlight are:

  • Ability to sense when motion is detected and turn on other lights.
  • Remotely turn ON/OFF the floodlight under program control or via the web.
  • Operate the floodlight on a daily schedule and/or dim the light until motion is sensed.
  • The floodlight still operates normally when the motion sensor is activated.
    Update: The
Motion Activated Floodlight wired with Insteon In-LineLinc

Motion Activated Floodlight wired with Insteon In-LineLinc

The Insteon In-LineLinc is an ON/OFF relay module with a 120VAC sense input that is ideal for integrating with a Passive Infra-Red (PIR) motion sensor as commonly found on security floodlights. The User Guide is well written with detailed wiring diagrams.

Insteon In-LineLinc #2475S2 Module with Sense

Insteon In-LineLinc #2475S2 Module with Sense

Heath Zenith Floodlight Compatibility

The In-LineLinc is compatible with the PIR motion sensor on “standard” Heath Zenith floodlights (e.g. models SL-5412, SL-5408) as widely sold through home improvement stores. However, in my experience the In-LineLinc does not work with those Heath Zenith models having the Dual-Brite patented dimming feature. So be sure to get a floodlight without Dual-Brite.

Electrical Safety

The following involves working with 120 volt AC electricity that can kill, main or shock the daylights out of you! If you don’t know what you’re doing and how to comply with the electrical building code regulations, then stop and hire a professional licensed electrician.

Preparing the Floodlight

This is a brand new out of the box Heath Zenith #SL-5412-WH floodlight showing the wiring connections. The first thing to do is unbundled the wires by removing the two wire nuts as indicated by the red arrows in the following photo.

Note: This will probably void your product warranty! But it’s a ~$27.00 unit and are you really going to keep the receipt, box it up and mail it back to the manufacturer after 2, 3 or 5 years for warranty replacement if it breaks? Have you noticed those computerized cash register receipts tend to fade to the point it’s unreadable after a year or two? When I buy a really important item, I make a copy of the receipt to have a document that lasts.

Heath Zenith SL-2412 Floodlight Wires

Brand New Heath Zenith #SL-5412 Floodlight

The wire nut is crimped flat on two sides. Use pliers to uncrimp it and make the metal part round (or squarish) to release the wires.

Uncrimping the Wire Nuts

Uncrimping the Wire Nuts

After uncrimping the wire nut, pull gently to remove. This is what you have after the two wire nuts are released – see the red squares.

Wire Nuts Removed

Wire Nuts Removed

Untwist the red and white wires to separate the motion sensor wires from the lights. Discard the short white pigtail wire.

Untwist and Free the Wires

Untwist and Free the Wires

What you now have are:

  • Motion sensor wires – all operate at 120VAC:
    Black (line)
    – White (neutral)
    Red (sense), output is zero volts when no motion is present, 120 volts when motion is sensed.
  • Light socket wires
    Red (hot) x 2
    – White (neutral) x 2

Weatherproof Electrical Box

I chose the Red Dot (by Thomas & Betts) weatherproof aluminum electrical box to mount the floodlight to an exterior wall. These are available at Home Depot. It was necessary to combine a base box with an extension unit to make room for the In-LineLinc. The Red Dot D-Pak® Dry-tite® part numbers are:

Here are the two items:

Aluminum Box Extension and Outlet Box

Aluminum Box Extension and Outlet Box

The extension box comes with mounting screws, weather gasket and plugs for unused outlets.

Assembled Extension and Electrical Box

Assembled Extension and Electrical Box

The brass mounting bar for the floodlight fits perfectly and held by two screws in the normal way.

Floodlight Mounting Bar

Floodlight Mounting Bar

Trial fitting the foam weather gasket to seal between the electrical box and floodlight.

Weather Gasket

Weather Gasket

Installing the Floodlight and Wiring the In-LineLinc Relay

First, shut off the power to the floodlight circuit at the main electrical box. Do not rely on the ON/OFF light switch.

In the next photo, I’ve removed the old floodlight. The old floodlight was installed by perhaps the same numbnut electrician that wired my other light switch (search for ‘numbnut’ in that article). My guess the guy who installed the old floodlight cut the wire too short and drilled a new hole with only 2 inches of wire poking out. The floodlight was mounted directly to the wall without an outlet box. Another example of sloppy work by the lowest bidder!

Old Floodlight Mounting Bracket

Old Floodlight Mounting Bracket

The way to correct this error is caulk the unused holes and wire 8 inch long pigtails as shown:

Caulking the Holes and Wiring in Pigtails

Caulking the Holes and Wiring in Pigtails

The new electrical box is mounted to the wall with two screws and the wires nutted together. The back of the box was sealed against the wall with a length 1/2 inch thick foam weatherstrip to keep out rain and bugs.

Surface Mount Electrical Box

Mounting the New Electrical Box

The In-LineLinc and floodlight wiring connections are made per the floodlight wiring diagram on page 5 of the 2475S2 User Guide. The 2475S2 wiring connections are:

  • Bare copper ground wires all wire nutted together.
  • Black (hot) house line wire to the In-LineLinc black “line” and red “switch-in” wires.
    The black house line wire is connected to a standard On/Off toggle wall switch on my home. It’s important to leave the wall switch On so the In-LineLinc is always powered for remote Insteon control.
  • White (neutral) wires all nutted together.
  • Floodlight lamp red wires nutted to the In-LineLinc red “switch-out” wire.
  • The floodlight PIR red sensor wire is connected to the In-LineLinc Yellow “sense” wire.
    If the floodlight PIR sensor senses motion it will signal the In-LineLinc to turn On the floodlight. Or you can remotely command the floodlight with an Insteon controller to turn On or Off the light.
In-LineLinc and Floodlight Wiring Connections

In-LineLinc and Floodlight Wiring Connections

The In-LineLinc and wires are gently folded and pressed into the electrical box. The floodlight is fastened with a large screw to the center hole of the brass mounting bar. Not shown for clarity is the foam weatherseal between the box and floodlight.

I found it necessary to shorten the 2 inch long mounting screw by about 3/4 inches with a Dremel tool cutoff wheel, because the screw was so long that it hit the body of the In-LineLinc. Do not use bolt cutters because it will damage the threads.

In-LineLinc and Wires ready Final Assembly

In-LineLinc and Wires ready Final Assembly

The light is now fully assembled and ready for use.

Motion Activated Floodlight wired with Insteon In-LineLinc

Motion Activated Floodlight wired with Insteon In-LineLinc

Device Linking and Floodlight Scene

A different floodlight by the kitchen door is controlled by a ToggleLinc On/Off wall switch. I linked the lower deck floodlight containing the In-LineLinc (responder) to the ToggleLinc (controller) via the ISY Insteon Home Automation Controller Administrative Console via a scene named “Kitchen Deck Floodlight”.

Floodlight Scene in the ISY-99i Admin Console

Floodlight Scene in the ISY-99i Admin Console

The way the two floodlights work is:

  • The newly installed deck stair floodlight (i.e. In-LineLinc) turns ON/OFF when the motion sensor is triggered.
  • The deck stair floodlight turns ON when the kitchen floodlight (ToggleLinc switch) is manually turned ON by flipping the switch via the scene. This lights up the main deck and stairs together on opposite ends of the house. Very convenient!

Other cool things to do are an ALL ON command and writing programs to turn on other lights when motion is sensed by the In-LineLinc floodlight. I also can control everything via any Internet connection and web browser, too!

Take care,

Bob Jackson

Copyright © 2018   Reproduction strictly prohibited.


  1. Patrick Smith December 19, 2014 at 11:36 am - Reply

    Hi Bob, just wanted to say thanks these articles and the pictures. I found your site searching for info on setting light timers from Insteon motion sensors… but I also have an LED floodlight disassembled on my desk in front of me because I was going to do the same thing you did here. Pretty cool. I checked out some of your other articles and they all look very interesting. Added your site to my favorites so I can check back. Thanks, Patrick

  2. Pete K July 20, 2015 at 10:29 pm - Reply

    Hi Bob, Looks like “Insteon In-LineLinc #2475S2 Module with Sense” is no longer available.

    INSTEON 2475SDB InLineLinc Relay Remote Control InLine On/Off Switch

    Doesn’t have the same “sense”.

    Any suggestions?

    • Bob Jackson July 21, 2015 at 9:35 pm - Reply

      Yes – the In-LineLinc #2475S2 with an external “sense” input wire for the floodlight motion sensor signal has been discontinued. The problem is the newer In-LineLinc 2475SDB lacks the sense wire and therefore can’t be commanded by the floodlight PIR sensor.

      I’ve updated the project with an alternate approach using the Insteon 2420M wireless motion sensor with the newer 2475SDB In-LineLinc, which refers to this project: Automate Exterior Lights with an Insteon Wireless Motion Sensor.


      • Russell March 9, 2017 at 12:22 am - Reply

        Wouldn’t this work well with the Insteon Micro On/Off switch adapter. It has a sense wire. Item #2443-222 from Smarthome.

        • Bob Jackson March 9, 2017 at 7:52 am - Reply

          The 2442-222 Micro switch should work and I bought one test it with a floodlight. Haven’t gotten around to doing that yet.

          • Paul Earhart May 13, 2017 at 6:25 pm - Reply

            I have tried using a 2443-222 micro switch and a HeathZenith #247582 (SH-5316-BZ) motion sensor without any luck. I have the load wire from the motion sensor connected to the yellow sense wire of the micro switch. When there is motion, 120vac is present on the yellow lead but has no effect on the micro switch (in latching mode). Tried to get help from
            Smarthome without any luck.

            • Bob Jackson May 13, 2017 at 7:19 pm - Reply

              I also bought a 2443-222 micro switch intending to do the same because the Insteon In-LineLinc 2475S2 has been discontinued. I won’t know if it will work until I experiment on the workbench. Let me know if you figure it out.

              • Paul Earhart May 14, 2017 at 5:06 pm - Reply

                I’m having no luck at all. I tried two other motion sensors, a Defiant model DF-5716 and a Utiltech model GYQ27. Neither worked! Just to be sure, I connected a SPST switch in place of the motion sensor and that worked as expected
                The micro switch specs don’t give any requirements for the yellow sense wire but if I’m looking at the schematic correctly, it’s got to be line voltage. I checked the voltage from the output of the motion sensor when it was
                tripped, and it was only around 10 VAC when hooked to the micro switch and over 100 VAC when hooked to a 60 Watt light bulb.

                If there is a work-around, that’s certainly above my pay grade.


                • Bob Jackson May 14, 2017 at 5:11 pm

                  I’ll try it myself in the next week or two. Maybe a non-dimmable LED floodlight bulb will work? A 13-watt LED is the equivalent of a 90-watt incandescent bulb. A standard bulb might be overloading the Insteon micro-switch.

  3. pierce.jason October 31, 2015 at 2:29 pm - Reply

    It would appear that the Insteon micro modules 24X-22 (where X eq. 2 or 3) have the necessary sense input for the light’s built in motion sensor to function.

    • Paul Earhart May 16, 2017 at 2:44 pm - Reply

      I got it working by connecting a solid state relay between the motion sensor and the micro switch. The motion sensor load controlling the relay (input) and the relay (output) controlling the line voltage to the sense wire.

  4. Brian January 2, 2018 at 1:42 pm - Reply

    Hi Bob … I found your helpful posts after already installing one of the Heath Zenith flood lights with DualBrite. Do you think this setup will work as long as that feature is turned off, or was your experience that the DualBrite feature gets in the way regardless?

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