Use Truck Input for rear hatch?
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=41293
Printed Date: May 12, 2025 at 9:09 PM
Topic: Use Truck Input for rear hatch?
Posted By: ampere
Subject: Use Truck Input for rear hatch?
Date Posted: October 20, 2004 at 10:18 AM
I am going to be installing a Viper 791 in an 04 Escape and I'm planning out everything right now. On thing I just realized is that the liftgate (and liftgate glass) are considered a 5th (and 6th) door. So, the truck doesn't really have a trunk per-se and therefore the trunk input on the alarm would not be used. However, I'd like to be able to utilize this Zone so my fob will be specific in telling me the hatch is open, and not just another door. Ford's wiring diagram indicates that there is a voltage from a GEM to ground through the liftgate, and liftgate glass. Therefore, when one is opened the circuit it broken. (Thus, me splicing in would get me a positive (+) voltage when either are opened. Seems to be a simple, unless I am overlooking something. My question is this: In order to use the hatch and glass for the trunk input, I have to isolate it from the domelight system (which would indicate a door being open), this will cause my domelights to not light when the hatch is opened. If I do not isolate the hatch, my FOB will indicate trunk and door being open. Because of the GEM module just creating a voltage difference and no current, I'm not sure diodes would work, but PLEASE correct me if I am wrong.:errr:
Replies:
Posted By: gus1
Date Posted: October 20, 2004 at 12:30 PM
GEM is located under radio area, centre of dash, remove the pieces forward of centre console. Once there.... all door inputs to the GEM are negative trigger, meaning they go to ground. You can get all of the doors, the hatch, and even hoodpin if so equipped. Diode isolate accordingly, you'll be fine. The 791 will see an input on the blue wire as a trunk only, and show accordingly on the display. Hoodpin is the grey on the same harness as tach, brake, 2nd status, etc.
Gus
------------- Wherever I go, that is where I end up......
Posted By: ampere
Date Posted: October 20, 2004 at 1:15 PM
gus1]G wrote:
M is located under radio area, centre of dash, remove the pieces forward of centre console. Once there.... all door inputs to the GEM are negative trigger, meaning they go to ground. You can get all of the doors, the hatch, and even hoodpin if so equipped. Diode isolate accordingly, you'll be fine. The 791 will see an input on the blue wire as a trunk only, and show accordingly on the display. Hoodpin is the grey on the same harness as tach, brake, 2nd status, etc.
Gus
Thanks for your input! I understand that if I tap into the negative trigger hatch wire and run that to the alarm, it will show the trunk as being open, however, won't it still show that a door is also open?
Posted By: gus1
Date Posted: October 20, 2004 at 3:34 PM
If it has a separate trunk pin. Then yes, if you connect the blue trunk wire to it it will show up as "trunk" on the display. If the vehicle does not have a separate trunk wire per se, then run one back to the switch for the rear hatch.
Gus
------------- Wherever I go, that is where I end up......
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