Trunk release wiring info needed - want to add release on trunk lid

[mjs001]

That works like the one on my BMW did - push the button above the license plate and as long as the car is unlocked, the trunk opens. If the car is locked, the button does nothing. Is there any body control output on this car that is energized when the car is unlocked but not when the car is locked?

That way I can toss my luggage into the trunk while the keys are still in the ignition.

[norm8332]

I believe it has to be unlocked to open the fuel door. Check there.

[vipz28]

hmmm this is a good idea, please keep us in the loop, and take lots of pictures during your install

[-Ray-]

The unlock is in the glove box. The doors don't have to be locked/unlocked for that circuit to operate.

[Greg@PacePerformance]

It looks like if you do use the fuel door actuator wiring you will need to wire in a relay because it gets it voltage from the BCM.
Now thinking about it I don't think the BCM will supply constant voltage to the actuator while the door is unlocked so that might not work either.

[mjs001]

Looks like I'll have to run a wire from the glovebox switch. I checked, and the glovebox switch behaves the way I want - it opens the trunk only when the car is unlocked, whether the ignition is on or off. Hope to have the chance to do a test wiring this weekend.

[mjs001]

Greg - you're right. The fuel door latch works just like one of the power door locks. Pulse sent to the unit, not continuous voltage.

[ETIDMotorsports]

This is an awesome idea. Please keep us posted.

[zepcom]

That's a great idea. My mother in law just took delivery of a 2010 GMC Terrain and it has a cool rubberized weatherproof "button" under where the license plate frame is. Not sure if you can research/source that part, but that could potentially provide the button functionality at the trunk area, as well as be weatherproof already.

This is a great project for sure.

-zepcom

[MAYBEN]

I always liked how BMWs and others have this feature

[mjs001]

Installed the outside trunk release button. Pretty simple install, just had to learn how to disassemble the interior of the car. Ran a wire from the glovebox trunk release button to a switch installed above the license plate. Not too hard to do. Major steps:

1. Remove glovebox (well covered in several gauge install posts)
2. Pull cover from passenger side of console (clip directly below grab handle and one about 2 inches forward of the back edge)
3. Remove rear seat lower cushion (pull straight up on front corners of seat, about 6 inches in from end. The spring clips are very tight - it takes a good yank to release.
4. Remove passenger rear seat cushion by remove two nuts on bottom and lift cushion straight up to remove.
5. Open trunk and pull rubber wiring guide from the trunk lid and body below rear window.
6. Remove trunk lid liner
7. Remove plastic cap from the hole immediately above the license plate by squeezing and pushing out from inside the trunk lid.
8. Find a momentary contact normally open pushbutton switch that will fit in a 3/16 inch hole. I got a 4 pack at radio shack for a few bucks. Really cheap switches, though. I'm still looking for a weatherproof switch.
9. Route the wire from the trunk lid to the glovebox. through the trunk deck, through the rubber wire guide (between the trunk lid and body just below the rear glass) and through the hole in the body just below the glass.

The wire is now in the cavity above the trunk liner and below the rear deck. I taped the wire to a stick and fished it thorugh a hole from the trunk to the area behind the back seat. I used an electrician's fish wire to get the wire from the center of the back seat to the opening under the center console. The carpet is glued to the padding; fishing the wire is easier if you pull the carpet and pad apart over the top of the trans tunnel.

Once the wire is into the console, route wire to glovebox area and tap into the wires that feed the glovebox switch.

The switch works exactly as it should - it opens the trunk only when the car is unlocked. No more reaching inside the car to find the key to open the trunk.

[mikemaj82]

i'm assuming this is for people who use the key to unlock the doors instead of the FOB? Because if you unlock the doors with the FOB chances are you use it to pop the trunk too? I don't really understand the purpose of this...

[mjs001]

It's easier for loading the car. I park the car in the garage and leave the keys in the ignition. Every Monday when I leave for the airport, I don't have to stop, open the driver door, pull the key, push the trunk release, put stuff in trunk and then put key back in ignition when I get in the car. It's a feature I never thought about unitl I drove a BMW and I was surprised how often I need to get into the trunk without having the keys with me.

[Bhuge]

I applaud your ingenuity. I just don't need to get into the trunk that often. Do you have any pics of where the button is mounted.

[mjs001]

Pic of trunk release button. It is located immediately below the Pontiac emblem on the trunk. A black plastic plug is in this hole from the factory.

http://www.flickr.com/photos/mjsejs/4435372207/

[GT Drew]

You must live in a crime free area. I Never leave my keys in the ignition. That way I always have the remote to unlock the trunk

[r33pwrd]

Pic of trunk release button. It is located immediately below the Pontiac emblem on the trunk. A black plastic plug is in this hole from the factory.

http://www.flickr.com/photos/mjsejs/4435372207/



I would use something like this (see link) as im sure that switch you are using is not sealed. If you want one of these let me know I have a bunch of them sitting around.
(this is a white one but I have black)

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=679-1130-ND

[TurboMike]

You know I read this thread a while ago and didnt think anything about it but now everytime I go to the back of the car and cant open the friggin trunk it pisses me off. I think I'm gona do it. Did anyone look in the shop manuals and look for an easiler place to tap into the glove box button instead of going all the way to the glovebox?

Where did you run the wire from the trunk to the glove? I ran VIM wires under the back seat to the back of the center console and it was a whore to fish them under the carpet. Is there an easier way I dont know about?

[TurboMike]

I would use something like this (see link) as im sure that switch you are using is not sealed. If you want one of these let me know I have a bunch of them sitting around.
(this is a white one but I have black)

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=679-1130-ND

What size is that button? Wondering about how it would sit in one of the three seals above the lic plate.

[mjs001]

The existing hole is only less than 1/4 inch, maybe 5 - 6 mm. I haven't gone looking for a sealed switch yet. I know many vehicles have external switches. Nissans use a neat switch embedded in the door handles and trunk as part of their keyless proximity system, and someone has already mentioned the GMC Terrain uses a sealed switch I'm sure a better option exists.

I ran the wire the same way you did. Not too bad using an electrician's fish tape. When you run a wire through there, always pull a spare to use for pulling the next wire through. Then you never have to fish again.

[jerluv2]

I have a customer with a 2009 jag XK-R, and there is a small round momentary push-button switch for the hatch on it. If it's not ungodly expensive, I think it would be just what you need. Also check the rubber pad-like switches on the trunk of the Cadillac CTS or STS, or the outside door open switch from an XLR (I know they're only like $15).