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I'm updating the head unit in my 2000 XJR with the premium audio and need to find a reverse signal close by that I can tap into so I can use the camera. Electrical guide shows multiple yellow wires from the SLCM for nav, rear view mirror, parking module, trailer etc but mostly in the trunk and nothing seems to be nearby. Lots of posts on Stereo upgrades but haven't found anything that mentions this connection.
Can anyone who's done this before let me know where you tapped into the reverse circuit? I'll power the camera transmitter from the trunk connections but hoping to avoid running a wire from the trunk to the head unit.
Dang these Vero Bch people and their upgrades....lol j/k Mike....I'm just on the East side of Orlando
I'm all but positive you'll have to run that wire for the cam simply for the grounding shield. There is a thread (at least I hope it still exists with the recent site update) where someone had put an audio jack plug in on the face OE head unit for their phone. Wow, this took me 45 minutes to chase down this old thread... https://www.jaguarforums.com/forum/x...ve-one-103359/
I ran new wire for my head unit when I did that back in '16, eliminating the factory amp/cd/nav unit and putting in my own, ...but used the existing leads for the new speakers. I don't have a cam.
Pulling the rear seat isn't hard, and fishing the wire from the trunk is easy actually...in the small pic when you pull it, I marked is where I fished from the trunk then up under the carpet into the center council. The fishing point is the same on either side of the trunk right where I note the orange arrow. You can fish a semi rigid wire through there.
Wow, this took me 45 minutes to chase down this old thread. This feed is down the C pillar, but is high to bring wire behind the seat. Just giving ideas there are fishing points... https://www.jaguarforums.com/forum/x...ve-one-103359/
I added the stereo schematic for comparison for whether you have it or not.
From you using “transmitter” in your post I understand the camera is wireless. I did a wired installation in my 911.
Tapped into wire at reverse light for the reverse signal only and not power for camera. Remember directions said if use same for camera power you’ll blow a fuse. Unit had plugs for camera video and power. Can use camera while driving by pushing button.
Thanks HighHorse! I read the post for the antenna delete and 20 minutes later had the wire run through the C pillar ready to go. Definitely easier than trying to find the elusive reverse wire that runs to the rear view mirror and exactly the sort of knowledge that this forum is so good at sharing. The Vero Beach upgrade challenge has been completing a project like this in the heat of the summer. Weather's starting to cool a little so now's the time to try to get this done. We've also moved to Melbourne, not that it's any cooler, but now a little closer to your part of the state. Need to update my profile.
Pcolapacker you make a good point about the current draw for the camera. Yes, it's a wireless connection and I just need the signal wire to tell the head unit to display the camera output when reverse is selected. I checked into the spec for the camera/transmitter combo. It's rated at less than 300mA so quite a bit less power draw than hooking up the trailer connector to a trailer so thinking it'll be ok connected there. I might still look into keeping it live so it can be used when not in reverse.
When I saw transmitter, I perceived simply the activation, glad pcolapacker highlighted that...so yeah, a wireless unit is neat. Glad that thread helped.
I haven't dug into a wiring diagram to find out, but I would think that the J gate shifter assembly would have a wire that "knows" when the shifter is in reverse. The wire going into the head unit just has to sense 12 volts, it doesn't actually power the camera. When you shift into reverse, it senses 12 volts at the reverse wire, turns on the camera, and switches the display.
Somehow the car "knows" when the shifter is in reverse, so in my mind, that has to either happen at the J gate assembly, or inside the transmission. If it's inside the transmission, then the only option is probably to run a wire into the trunk and T into a reverse light wire as suggested above. If it's in the J gate assembly, then perhaps a T splice can be made there someplace.
Perhaps someone knows if there is a wire coming out of the J gate assembly that carries 12 volts when in reverse. Otherwise it's off to the electrical diagram!
I haven't dug into a wiring diagram to find out, but I would think that the J gate shifter assembly would have a wire that "knows" when the shifter is in reverse. The wire going into the head unit just has to sense 12 volts, it doesn't actually power the camera. When you shift into reverse, it senses 12 volts at the reverse wire, turns on the camera, and switches the display.
Somehow the car "knows" when the shifter is in reverse, so in my mind, that has to either happen at the J gate assembly, or inside the transmission. If it's inside the transmission, then the only option is probably to run a wire into the trunk and T into a reverse light wire as suggested above. If it's in the J gate assembly, then perhaps a T splice can be made there someplace.
Perhaps someone knows if there is a wire coming out of the J gate assembly that carries 12 volts when in reverse. Otherwise it's off to the electrical diagram!
I’ve been digging through the electrical guide for hooking up my LS to the Jag electronics. Look at Fig. 5.2. There is a gear selector illumination module that feeds the 7 LEDs. Maybe can tap there. The module gets its info through the CAN. I’m no expert. Hopefully someone else will chime in before you do any splicing.
The switch by the J gate looked to be the best option when I first looked at this but it seems to use different resistance levels to feed a voltage value into the CAN bus via a controller. The CAN bus communicates with the SLCM to set a 12v line for the reversing lights etc.. I need the 12v line rather than the different voltages for each gear so the j-gate switch wont help. There is a line running forward from the trunk that goes to the rearview mirror, the other reversing signals stay in the trunk. I was hoping to find that line in the passenger cabin rather than have to route a line from the trunk.
I did find the location in the picture for a connector above the fuel tank that goes into the passenger compartment (yellow wire in top right corner). I tapped the wire near the wheel well and close to the C pillar and ran the line through the c pillar and under the seat as HighHorse suggested. In my case the wire is providing both the 12v signal to tell the headunit to show the camera and is also powering the camera/transmitter. Both connections are spliced in at the same point.
Quick lessons learned from completing this job and for the steps not covered in other posts
1/ Easiest location to find a reverse signal in the passenger compartment is the yellow wire on the connector for the rear-view mirror behind the overhead console. It's likely you'll be running a microphone wire to the same point so both wires can be routed under the headliner, over to the driver's side a-pillar and then behind the instrument cluster to the center console. Alternatively, you can run a wire from the trunk as discussed above.but there is a little more stuff to remove to get it done.
2/ The wire to hook up the steering control in the yellow connector going into the old head unit may not be red/white as shown in the electrical guide wiring diagram. A previous poster had the same problem finding it. On my car it was green/brown and works just fine once found.
Otherwise, the previous posts have it covered. I still have to securely attach the screen and will need to adjust the camera so it's level but almost done.
Quick lessons learned from completing this job and for the steps not covered in other posts
1/ Easiest location to find a reverse signal in the passenger compartment is the yellow wire on the connector for the rear-view mirror behind the overhead console. It's likely you'll be running a microphone wire to the same point so both wires can be routed under the headliner, over to the driver's side a-pillar and then behind the instrument cluster to the center console. Alternatively, you can run a wire from the trunk as discussed above.but there is a little more stuff to remove to get it done.
2/ The wire to hook up the steering control in the yellow connector going into the old head unit may not be red/white as shown in the electrical guide wiring diagram. A previous poster had the same problem finding it. On my car it was green/brown and works just fine once found.
Otherwise, the previous posts have it covered. I still have to securely attach the screen and will need to adjust the camera so it's level but almost done.
I haven't looked for the wire in mine yet, and I certainly believe you, but why is there a reverse signal wire in the overhead console? I will definitely use that wire, I just can't figure out what its purpose would be up there?
I agree it does seem odd but the reversing lights are connected to the rear view mirror tint. It's called out in the electrical guide for the lighting circuit. Maybe it prevents the mirror auto dimming when going backwards?
I agree it does seem odd but the reversing lights are connected to the rear view mirror tint. It's called out in the electrical guide for the lighting circuit. Maybe it prevents the mirror auto dimming when going backwards?
I read the post above yours & was going to guess exactly that about the autodim for the reason.
09-24-2023, 10:06 AM
Stereo Update - Reverse Signal Wire location?
