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... I assume that can be programmed for my Acadia but would ther be an issue once it was programmed for the outlook?
When an exchange BCM is properly flashed with your vehicle's programming, any information with respect to donor vehicle specifics is wiped out.
 

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Discussion Starter #22
I checked the lamp bulbs in rear hatch and both appear to be good. I did not actually pull the panel and disconnect the harness to full test the theory but I pulled the lamps and checked the bulbs. I also manually operated all the internal lamps and the work with the buttons near the lamp.
 

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Discussion Starter #23
So I’m sitting in the car now.. I have pulled the overhead dome console and I’m testing with lamp for power. I have power coming into lamp on purple w/wht, red w/wht, gray, orange. I do not show any power coming from the gray w/blk. If BCM is sending signal should I see power on this Gray/Blk wire?
 

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As long as the courtesty lights are ON (be sure to check that overide switch!), you should see power to them. Gray/Black is power for the courtesy lamps - orange is power for the map light.
 

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Discussion Starter #25
Ok.. so if I don’t have any power on the gray w/blk coming into the overhead panel do you feel it’s likely the BCM that is not working? I also pulled the headlight switch and I have the purple w/wht that has power and the green appears to be for the dimmer and will have power when turned to on. I do not have any power to the pink w/blk in the switch.
 

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Check to see if the Grey/Blk is grounded. I suspect a short to ground. I would be nice if you could access all the connectors and disconnect them one by one. I would hate to see you go through the expense of buying it, programming it and not have this PITA solved. And if there is a short, it may or may not cause the BCM dimming feature to go bad, but if you still have a short, it may, (or may not) cause the new BCM to go bad. Sounds like the issue that Tynee had, was possibly a bad bulb caused a low resistance to ground and caused his issue, it looks as though his BCM recovered. I don't believe that two burned out bulbs caused his to go and miraculously cure itself with a new bulb, I believe something else was disturbing the wiring inside the Liftgate. I know that I get water in mine, droplets come out of the interior rubber membrane closing switch.
 

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If you can take off the connector for the lights, the one with GR /BK, at the BCM. First check for a short to ground, Take a wire from the positive source, with a separate inline testing fuse, say 5 amp, and jumper it to that GR/BK # 690 wire and see if the lights come on or if the fuse blows.
 

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Discussion Starter #28
Ok... so if I’m following you correctly you are suggesting a run a wire day from the positive post of the battery and touch to the gray w/blk wire coming from the BCM. You are suggesting on the wire that between the battery and the gray/blk to just put a 5amp fuse to protect the components on that wire. I guess we would just be running a bypass of the BCM? If I’m following you correctly this sounds like a great idea...
 

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Ok... so if I’m following you correctly you are suggesting a run a wire day from the positive post of the battery and touch to the gray w/blk wire coming from the BCM. ...
You should be able to find a power source closer to the BCM than the battery post.
 

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Exactly. You may have a spare fuse inside the fuse box under the hood, sometimes they put spares in little bunnies , maybe even a fuse puller too.
 

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Discussion Starter #31
It’s a great idea.. I plan to test this tomorrow!! I may not sleep tonight dreaming that this is going to work!! :)
 

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Exactly. You may have a spare fuse inside the fuse box under the hood, sometimes they put spares in little bunnies , maybe even a fuse puller too.
Gotta be something closer than that, too - like near the ignition circuit. :unsure:
 

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Discussion Starter #33
Happy Memorial Day. Ok.. I tested first thing this morning and here’s what I did and what happened. I ran a wire from the fuse box under the hood. I have a handful of fuse taps so it was just easier to tap there. I pulled down the BCM but kept everything fully connected. I found the gray/blk wire in one of the wire blocks. I then pulled the overhead dome panel and checked continuity from that wire in BCM to the gray/blk in overhead panel to make sure it’s the correct wire. I then left the wire plugged into BCM but touched my 12V tap wire to the gray/blk from the back of plug going into the BCM. When I did this the fuse would immediate blow. I did not test by first pulling the plug from the BCM and touching the 12v tap wire to gray/blk going to overhead panel because there are so many other wires on that plug that I felt should likely be plugged during test... but I’m really not sure. I guess I expect that if I put power directly to the gray/blk that has continuity with the overhead panel that would light up... so wondering if given the manner that I tested by keeping plug in BCM is correct and if the fuse blowing would indicate a short to ground?
 

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Discussion Starter #34
Curiosity got the best of me... so I pulled the plug from BCM and also tested by connecting 12v tap to gray/blk and fuse also blew right away...
 

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First place I would check for a short would be in the hatch. And are you able to read the resistance on that wire to ground? I assume it is a dead short.
 

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Discussion Starter #36
I’m fishing all over this thing now... :)

With the gray/blk unplugged from BCM I measure continuity to dome panel and rear lift gate left and right lights at about .6 ohms at 200 setting
 

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Resistance of gray/blk to ground is about .4
Gotta short somewhere! Resistance of an open circuit should be near infinity.
 

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Yes, but he is also reading the resistance of the bulbs in the connectors to ground. I just checked mine at the rear hatch.
Both hatch bulbs in = .8 ohms to ground
One hatch bulb in = 1.1 ohms
Neither hatch bulb in = 1.4 ohms all on gry/blk wire to gnd.
My bulb in the rear may be different from yours. are yours miniature or a long tube with the connections on each end?
I calculate the current with just the 6 map lights would be 2.4 amps, we would need to figure in a higher current and different resistance if yours had the longer bulbs.
These are what my rear hatch bulbs look like. I believe they are a different wattage than my maps lights, but same design.
 
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