Rear Hatch Wiring Question

[beho88]

Hi All,

I'm new to the forum, just picked up a 99 T4R Limited! (really excited). I began installing an indash with rear view camera but can't find a wire to tap into. I searched all over the forums but can't find a wiring diagram. I have a multi meter but no clue how to use it.

Does anyone have a wiring diagram for the lift gate hatch so I can find a grounding point, a trigger wire (that turns on only when car is in reverse), and a constant 12V when car is on so I can have the camera on at all times incase I'm towing.

I can't run the wire down into the tail light because I routed the Video Yellow Cable through the stock wiring down the inside of the window. The yellow video cable has a red wire connected off the end which I used to plug into the backup sensor on the deck itself.

Any help is greatly appreciated! Thanks!

PS. All the other write ups i've seen on this website doesn't show which wire to use in the tail gate for those 3 things. Thanks again!

 

[James_BOND]

I have always wanted to do something similar to what you wanted to do but never had the $$ for it.

Anyways, to help you with the wiring...

From what I understand, the camera is going to be
installed close to your LP right?

also, are you saying that
there is going to be a trigger wire to turn the camera
on and off or only when you are in reverse?
because you said you want it on all the time you
are towing while driving or just backing up?

You can ground virtually anywhere.

If you need a 12V source in the back,
You can highjack from the 12V
plug at the rear end at your right.
If you need it in the front, then you also
have the 12V source from the Cigarette lighter(CL)
Both turn on when the car is on.

Also, a quick tip, fuse all your 12V connections with a 5A-10A fuse.

 

[TheDurk]

On a '99, the key-on power comes through the BLUE wire to the Back Door ECU. Full-time power comes through the YELLOW wire. Ground circuits are all WHITE w/BLACK stripe.

There is no circuit tied to the reverse circuit in the tail gate . You'd have to tap the reverse bulb in the taillight (RED w/YELLOW stripe) and run a new wire through the harness into the liftgate if you must have it there.

 

[beho88]

I have always wanted to do something similar to what you wanted to do but never had the $$ for it.

Anyways, to help you with the wiring...

From what I understand, the camera is going to be
installed close to your LP right?

also, are you saying that
there is going to be a trigger wire to turn the camera
on and off or only when you are in reverse?
because you said you want it on all the time you
are towing while driving or just backing up?

You can ground virtually anywhere.

If you need a 12V source in the back,
You can highjack from the 12V
plug at the rear end at your right.
If you need it in the front, then you also
have the 12V source from the Cigarette lighter(CL)
Both turn on when the car is on.

Also, a quick tip, fuse all your 12V connections with a 5A-10A fuse.

Awesome! Yes, I want one wire that will always leave the camera on incase I need to see whats behind there while driving ( can switch on to the camera from the HU manually), and also a trigger wire so my HU will know when I'm in reverse.

 

[beho88]

On a '99, the key-on power comes through the BLUE wire to the Back Door ECU. Full-time power comes through the YELLOW wire. Ground circuits are all WHITE w/BLACK stripe.

There is no circuit tied to the reverse circuit in the tail gate . You'd have to tap the reverse bulb in the taillight (RED w/YELLOW stripe) and run a new wire through the harness into the liftgate if you must have it there.

Great! Thank you! Really appreciate it. Since there is no reverse wire in the tail gate, is there one I can tape into by the front HU/driver side instead? I only wanted to run it that way because the Yellow Video cable connecting to the camera has a small power wire coming off each end. I can just discard that if I can tape into one of the wires near the HU.

 

[TheDurk]

Great! Thank you! Really appreciate it. Since there is no reverse wire in the tail gate, is there one I can tape into by the front HU/driver side instead? I only wanted to run it that way because the Yellow Video cable connecting to the camera has a small power wire coming off each end. I can just discard that if I can tape into one of the wires near the HU.

Yeah, the right side back-up light wire goes right to left in the main cowl wire just under the dash. It's RED w/ YELLOW stripe and passes through Pin 19 of Connector II3 which is on the right side of the dash above the glove box (26-pin connector). The two sides hook up in the relay panel by driver's knee (on the back of fuse panel) at Pins 1 and 4 of Plug 1D on page 24 of attached. Attachment is from 2002 but '99 is the same.

 

[IBallEngineer]

Great! Thank you! Really appreciate it. Since there is no reverse wire in the tail gate, is there one I can tape into by the front HU/driver side instead? I only wanted to run it that way because the Yellow Video cable connecting to the camera has a small power wire coming off each end. I can just discard that if I can tape into one of the wires near the HU.

Let me see if I understand, the camera gets power from the "small power wire" that is attached to the RCA video cable, correct? So one end should connect to the camera itself, and the other end to a 12V source. The easiest way to do what I THINK you want to do is to use a relay. Using a Bosch style 4 or 5 pin relay would be easiest. Run fused power to term 30, connect the "small power wire" to term 87. Connect terminal 86 to a good ground. Connect terminal 85 to a switch from fused ignition power, AND connect it to the reverse lamp circuit. This will allow the camera to ALWAYS come on when in reverse, and if you activate the switch as well.

Now as far as tapping in near the HU, I'll give you an idea, but [MENTION=10169]TheDurk[/MENTION] will need to confirm and supply more info or actual EWD pages since I don't have the 99 EWD. But on the later EWD you could pick up the 12V circuit after the back up light switch. You can do this either at the switch itself(not recommended), or at the connector ll4 pin 19 in the vicinity of the glove box. Again I don't have the links or the actual EWD to share. If any of this is unclear ASK QUESTIONS please.

:couch2:

 

[IBallEngineer]

You can also tap the reverse light circuit at the drivers side Junction block, connector 1D Pin 1 !

:hiding:

 

[TheDurk]

You can also tap the reverse light circuit at the drivers side Junction block, connector 1D Pin 1 !

:hiding:

I'm gonna throw the popcorn at you, but I can't find you.

Yeah, the right side back-up light wire goes right to left in the main cowl wire just under the dash. It's RED w/ YELLOW stripe and passes through Pin 19 of Connector II3 which is on the right side of the dash above the glove box (26-pin connector). The two sides hook up in the relay panel by driver's knee (on the back of fuse panel) at Pins 1 and 4 of Plug 1D on page 24 of attached. Attachment is from 2002 but '99 is the same.

 

[TheDurk]

Let me see if I understand, the camera gets power from the "small power wire" that is attached to the RCA video cable, correct? So one end should connect to the camera itself, and the other end to a 12V source. The easiest way to do what I THINK you want to do is to use a relay. Using a Bosch style 4 or 5 pin relay would be easiest. Run fused power to term 30, connect the "small power wire" to term 87. Connect terminal 86 to a good ground. Connect terminal 85 to a switch from fused ignition power, AND connect it to the reverse lamp circuit. This will allow the camera to ALWAYS come on when in reverse, and if you activate the switch as well.

Now as far as tapping in near the HU, I'll give you an idea, but [MENTION=10169]TheDurk[/MENTION] will need to confirm and supply more info or actual EWD pages since I don't have the 99 EWD. But on the later EWD you could pick up the 12V circuit after the back up light switch. You can do this either at the switch itself(not recommended), or at the connector ll4 pin 19 in the vicinity of the glove box. Again I don't have the links or the actual EWD to share. If any of this is unclear ASK QUESTIONS please.

:couch2:

I put a similar unit into my son's BMW 'vert. The 'small power cord' was a 'detection' wire to pick up the reverse circuit in the rear, the video panel itself had a larger 12V+ with ground 2-wire power feed. There was some kind of relay function built into the unit. The detection wire was VERY small, like 24 AWG. I don't know if OP's is like that, so I'm just answering questions. There are lots of ways to skin this cat, but if he wants to use a switch, a relay somewhere is essential, unless he wants to leave the camera powered by a key-on circuit--which is probably fine--they don't draw much. Then the video panel is triggered by the detection wire when in reverse which is probably best picked up in the front. I think you can also turn on the video without any signal on the trigger by pushing a button on the unit for when he's towing--as long as the camera gets key on power.. Again, I'm not sure if OP's works this way.

If he wants the camera off when not towing or backing up, then a relay is needed. And yeah, the whole back-up circuit is identical '99 and '02 except the wire color changes from white/blue to Red/yellow. Also, '02 doesn't have the pin-out for the 5-speed reverse switch since no 5-speed in '02.

 

[IBallEngineer]

I'm gonna throw the popcorn at you, but I can't find you.

You have an uncanny ability to say the same thing as me! I think it is reassuring to people to read the same answers from both of us, gives us both credibility and makes it harder to make a mistake. Of course, I make mistakes all the time. Just not here.

 

[TheDurk]

You have an uncanny ability to say the same thing as me! I think it is reassuring to people to read the same answers from both of us, gives us both credibility and makes it harder to make a mistake. Of course, I make mistakes all the time. Just not here.

It's also reassuring to me that someone else comes to the same conclusion as I did. Plus our 'clients' get better service, since we aren't always both around. Two time zone sourcing makes a lot of sense in the forum advice business. I really enjoy the way we work together on these.

 

[pattycakes77]

When I put my backup lights in the kit had a switch for on/off/reverse so I had to tap into the reverse light power. I have a power probe so finding the correct wire was easy but I did tap into the wire up front under the driver side kick panel instead of running a wire from the tails all the way up front to the switch. You'll just have to either follow the wire from the tails or probe for power in the wires when you put it in reverse to find the right one.

 

[lukewzim]

2002 Wiring Harness in Rear Tailgate

Hello,

I was looking through the forums and cannot seem to find an answer to my question. I have a 2002, and my question is about the main wiring harness going into the rear hatch ECU. Which wires are power wires? I was told the solid blue wire was key-on power, but that seems to be constant power. I am looking for options for my backup camera, as it has LEDs that currently stay on when the car isn’t on. Any help would be appreciated.

 

[Skulking]

Hello,

I was looking through the forums and cannot seem to find an answer to my question. I have a 2002, and my question is about the main wiring harness going into the rear hatch ECU. Which wires are power wires? I was told the solid blue wire was key-on power, but that seems to be constant power. I am looking for options for my backup camera, as it has LEDs that currently stay on when the car isn’t on. Any help would be appreciated.

Are you looking for key on power so the lights are on any time the car is on, or are you looking for power that will only turn on when you are in reverse? If you are looking for only reverse power, there isn't anything in the rear hatch, but you can go to the reverse lights for it.