Wiring Pwr/liftgate to Aftermarket Alarm System

[TXFRDOwner]

I have a '07 Expedition with power Liftgate. I had a remote start alarm installed but I'm still using the factory remote because of the liftgate button. I wanna be able to only use the aftermarket remote. It has the option of "Trunk Release" ... Has anyone done this before ?

 

[ELVATO]

I'd probably ask the people who installed the alarm for you. Not too familiar w/ aftermarket systems, but I'd assume it powers a wire that you hook up to the trunk release motor when you press the trunk release button.

You'd probably be able to tell from a wiring diagram of the liftegate module/motor, which the shop should have.

This would be kinnda how you can unlock all the doors by feeding a signal to the security module, "tricking" it into thinking you pressed the unlock button on the driver side.

EDIT:

How does the lift gate work? Do you push a button and it opens, and do you have to hold it to open it? Same with close. Do you only want to open it, or do you want to have it open and close?

 

[TXFRDOwner]

Thanks, ... now that u mention the "button", I'm thinking I can just tap into the wire coming straight from behind that button on the dash. And it's only one touch open or close .. so that should be fairly easy. i got the diagrams for both the security module and the liftgate.... so it's just a matter of identifying the right wires. ... thanks again for the logic !

 

[ELVATO]

Yea, I'd assume the alarm does an impulse to positive (or possibly ground) when the trunk button is pushed. Identify what it is, and change polarity as necessary (could probably use a relay for that).

Since you only have one button on the fob, hook it up to the "open" button. Or, does the Expy only use one button for open and close?

 

[TXFRDOwner]

Thats the good thing about it, it only uses one button to open/close. So thats gonna be a piece of cake. I will post the diagrams just in case someone else with a 07-10 Expy wanna do the same. The only difference will be the type of aftermaket alarm system they have.

Thanks again.

 

[TXFRDOwner]

I have a "Code Alarm Remote Start Model CA-671" already installed on my Expy and it has a "Trunk open" Button on the remote (Located on the side of the LCD remote) You can see a picture here:
http://www.audiovoxproducts.com/images/common/CA671/addl/CA671_1.png

First thing first, I went online to lookup the installation manual for the CA-671. Once I found that, now I know which wire to tap into.

Installation Manual: http://documents.codesystems.com/701597.pdf

Opened up my Dash (middle woodgrain section) to get access to the Liftgate Switch Connector. The wire I need to tap into is gray/yellow.


Next, I spliced it together with my other wire (I picked this yellow 18 Gauge wire I had laying around), then fished it through the Dash panel, behind the foam padding until I reached my Alarm module. (Nice and Clean install, outta sight, outta mind)


On the Alarm Module, I tapped into the "TRUNK OUTPUT" wire to connect the yellow wire mentioned above and link the two together.
Note: color will vary depending on your alarm make and model, but in this case the wire was Red/White.

Last but not least, I set the fuse for the Trunk Polarity (On the Alarm Module) to Negative polarity.


Since the LiftGate Button on the Dash is used for both Open and Close action, it made this install very simple.
... Don't hesitate to hit me up if you have any questions.