Question about factory theft system, 2004 Pontiac GTO

[WickedGoat]

Hello from across the Pond here in the USA. My name is Matt and I own a 2004 Pontiac GTO, which as some you know, was built in Australia by Holden, based off the Monaro, and shipped here to the US. It is the only brand new car I have ever bought and one of the best things GM ever did, tapping the supply in Australia. I bought the car brand new December 31, 2004 and still have it today and plan on keeping for a long time to come. I found this forum on Google searching for Holden Monaro forums.

Here is the problem and question I have about my GTO. It came from Holden with a plain rear view mirror. I came across a rear view mirror in a junk yard from another vehicle that has Homelink, auto dimming, compass and temperature display, and map lights. The mirror is made by Gentex and it is a 341 model. I ordered a brand new wire harness and temp sensor for it and hooked it all up. It has constant 12+ power, switched 12+ power, ground, 2 wires for the temp sensor, and a wire for the lights to be tapped into the courtesy light wiring so that they turn on and off with the opening and closing of the doors. Everything is wired up right and the mirror works as it should with one exception.

When you lock the car and arm the alarm, the courtesy lights and now the maplight on the mirror shut off like they should. About 7-10 seconds later, the illumination lighting relay clicks and only the newly added rear view mirror maplights turn on and stay on. I disconnected the mirror power harness and armed the alarm again and while the relay clicked again, the light did not turn on because it was unplugged. I have the wire for the maplights tapped into floor foot well light harness, white and green wire I believe. My question for you folks is this... Is there a way to prevent the BCM from activating the lighting relay or should I tap a different wire for the lights? In order to counter this issue, I have both power wires tapped to switched sources. The negatives to doing this is the lights do not come on when the doors open and the Homelink (garage door opener) will not work unless the key is on the ON position. This kinda defeats some of the purposes of having this mirror.

Thanks in advance for any information and knowledge you guys can share.

 

[krusing]

G'day from down under

Not sure if this a similar issue/problem,
At one stage, I went to change the map reading lights in my 2002 VY Calaiss to LED's, and they wouldnt work when installed.
Being a sparky by trade, I got the multimeter out and checked the polarity of the sockets,
and found the positive is the body of the globe, not the tip of the globe,

Without messing with the wiring, I just put it all back together, it realy wasnt broken, so I didnt need to fix it.
In saying that, your 2004 Pontiac GTO [Monaro] may have the same wiring configuration,
which could cause a voltage feed back through the other globes/bulbs.
The other option I was thinking about,
maybe install some minature 12V relays in one/two of the circuits, that could keep the 2 circuits isolated so there is no feed back ?.

 

[WickedGoat]

G'day from down under

Not sure if this a similar issue/problem,
At one stage, I went to change the map reading lights in my 2002 VY Calaiss to LED's, and they wouldnt work when installed.
Being a sparky by trade, I got the multimeter out and checked the polarity of the sockets,
and found the positive is the body of the globe, not the tip of the globe,

Without messing with the wiring, I just put it all back together, it realy wasnt broken, so I didnt need to fix it.
In saying that, your 2004 Pontiac GTO [Monaro] may have the same wiring configuration,
which could cause a voltage feed back through the other globes/bulbs.
The other option I was thinking about,
maybe install some minature 12V relays in one/two of the circuits, that could keep the 2 circuits isolated so there is no feed back ?.

Somebody else, just today, suggested something similar. I found him on YouTube and he was installing a similar mirror in his GTO, except it didn't have the negative trigger light input wire.

I commented on his video and asked him about it and he suggested that I tap the door trigger wires instead of the floor light wire and he also suggested using a diode isolator on each wire to prevent the feedback. I guess I will do that and the problem should be solved. I guess I was kinda over thinking this and looking to see of the car was doing something that I could correct.

 

[krusing]

Somebody else, just today, suggested something similar. I found him on YouTube and he was installing a similar mirror in his GTO, except it didn't have the negative trigger light input wire.

I commented on his video and asked him about it and he suggested that I tap the door trigger wires instead of the floor light wire and he also suggested using a diode isolator on each wire to prevent the feedback. I guess I will do that and the problem should be solved. I guess I was kinda over thinking this and looking to see of the car was doing something that I could correct.

A diode is a good idea, but that depends upon the wattage and current draw by the device,
Where a Relay is a physical contact to isolate the device/s.

 

[WickedGoat]

A diode is a good idea, but that depends upon the wattage and current draw by the device,
Where a Relay is a physical contact to isolate the device/s.

Understood on the relay. Here is another interesting thing about this. When the maplight on the mirror turns on, after the alarm is armed and the illumination relay clicks, if I open the trunk (I think you guys call it the bonnet?), the maplight goes off.

Another guy installed the same mirror in his car and it did the same thing, but not right away. Don't know if he installed it on his own or paid a shop. But he was having the same problem and discovered the trunk trick. I tried it but the light came back on after a while. I don't know if this little tidbit complicates or helps clarify what is happening, but figured I'd mention it.

Thanks again for your replies. It sounds like I can fix this and it will function the way I want.

 

[krusing]

Understood on the relay. Here is another interesting thing about this. When the maplight on the mirror turns on, after the alarm is armed and the illumination relay clicks, if I open the trunk (I think you guys call it the bonnet?), the maplight goes off.

Another guy installed the same mirror in his car and it did the same thing, but not right away. Don't know if he installed it on his own or paid a shop. But he was having the same problem and discovered the trunk trick. I tried it but the light came back on after a while. I don't know if this little tidbit complicates or helps clarify what is happening, but figured I'd mention it.

Thanks again for your replies. It sounds like I can fix this and it will function the way I want.

Bit of Aussie Slang -
The Trunk = The Boot over here
The Hood = The Bonnet over here

 

[WickedGoat]

Bit of Aussie Slang -
The Trunk = The Boot over here
The Hood = The Bonnet over here

LOL, I knew it was something... been watching a lot of YouTube videos of Australians working on their Holdens and have been trying to pay attention to the slang. Good stuff!

 

[WickedGoat]

Just an update to this topic... I finally got back on this when I installed my JHP gauges on the dash. For the mirror map light, I ended up running 2 wires from the mirror trigger wire to the BCM and tapped the negative door trigger wires. Problem solved. The maplight comes on and turns off when either door is opened or closed. It does not come on when the other interior lights come on and there is no more feedback when the alarm is armed. I also did not need the diodes for this. Just wanted to update this and let everyone know that the mirror and gauges are in and working like they should be.

 

[Jolls]

Great work and fantastic to have the solution documented for others. I note that you are in Lebanon. I was at fort Lost in the Woods for a few years on exchange and had a few other trips in and out on courses and other visits. So we were almost neighbours.

I liverd in Saint Roberts, we always pronounce it with french accent and a silent T to make it sound fancy. Something it and Waynesville were not. I was a frequent visitor of the pub at Devils Elbow and always amazed at the range at BassPro in Springfield. When we first arived my wife asked about going to Daisys Health Spa until I told her that it was the local knock shop servicing the base. I laughed so hard when she told me she was thinking if taking a look. Is the Elbow still up and running?

I've had a few meals and beers in Lebanon and was there in 04 but I don't recall seeing an Aussie built GTO rocking the streets - something that would have stood out like dogs balls.

I imagine that a GTO would be as rare as rocking horse **** among the pickups and SUVs.

 

[WickedGoat]

Great work and fantastic to have the solution documented for others. I note that you are in Lebanon. I was at fort Lost in the Woods for a few years on exchange and had a few other trips in and out on courses and other visits. So we were almost neighbours.

I liverd in Saint Roberts, we always pronounce it with french accent and a silent T to make it sound fancy. Something it and Waynesville were not. I was a frequent visitor of the pub at Devils Elbow and always amazed at the range at BassPro in Springfield. When we first arived my wife asked about going to Daisys Health Spa until I told her that it was the local knock shop servicing the base. I laughed so hard when she told me she was thinking if taking a look. Is the Elbow still up and running?

I've had a few meals and beers in Lebanon and was there in 04 but I don't recall seeing an Aussie built GTO rocking the streets - something that would have stood out like dogs balls.

I imagine that a GTO would be as rare as rocking horse **** among the pickups and SUVs.

Small world! How about that? Ft. Leonard Wood!! I don't know if the Elbow is still going... I have only lived here since September 2013. I lived in New Jersey before we moved out here. That will also explain why you may not have seen a GTO during your time here. Love the analogy of rocking horse poop! Bass Pro has probably doubled in size since you last saw it. It is a landmark in Springfield.

Funny thing... two weekends ago, I was up at the garage playing with the car. I bought a 2005 instrument cluster for its overlay as it matches the JHP gauge font. I swapped the 2005 overlay on to my 2004 cluster and and I was programming the cluster. The garage faces the main street through town and let me tell you, it felt like street night at the track. The pick up trucks and Mustangs were going at it full force. They love their pick ups out here.

Of all places to meet someone familiar with where I live... the Australian website partially dedicated to a car I own...