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Reverse wire always gives 12v...?


captainkirk

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Howdy all. I've just installed a Boss Audio head unit and a backup camera in my 06 Ranger. Both work, but now I'm trying to get things wired so that the backup camera will activate when I shift into reverse, instead of having to wait for the head unit to boot all the way up and turn it on/off with the screen icon.

Even though I've followed the directions from both units, the camera display stays on - even when the Ranger is not in reverse gear.

I've tried connecting to the Black+pink wire in the fuse kick panel, and the Black+pink wire coming directly off the transmission - same result.

At Crutchfield Tech Support's recommendation, I tested with a multi-meter. And sure enough, the Black+pink wire in both locations is ALWAYS putting out ~12v, even when the tranny is in neutral.

The weird thing is, under these circumstances, I would expect the reverse lights to always be on - but they are not. They only come on when the tranny is in reverse.

Goin' crazy in Cali - can anyone give me a hint?
 


2011Supercab

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You need to find what color/s wire goes to the backup lights at the bulb.

Then find that wire at the transmission selector switch.


There is no wire inside the cab of the truck that powers on only in reverse.


The Black/pink wire is the power wire for the backup lights to the transmission switch, you need to find the wire coming out of the transmission switch that goes to the backup lights.
 

captainkirk

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Thank you for the response, @2011Supercab (and supporters)! I did realize that I had made a mistake when wiring things, which I corrected.

But I still can't get reverse gear to trigger the camera...

More info:
- The + wire feeding my backup lights at the bulb *is* Black/pink.
- The Chilton manual says it's supposed to Black/pink.
- One of the 2 wires coming out of my Manual Backup Lamp switch is also Black/pink - unless I'm looking at the wrong device? But based on the description of the location, and the pics I find of the unit online, I believe I'm looking at the correct device (small hex-sided brownish plug up high on left side, close to shifter).
- Crutchfield Tech Support also said it's supposed to be Black/pink in the cab (which is where they suggest connecting the Reverse input wire).

So here's what I did - I measured voltage, using better contact methods than previously, and alligator clip/jumper wires to hold stuff in place.

1. Voltage at Black/pink wire feeding the backup bulb: 0v in Neutral, 11.07 in Reverse
2. Voltage at Black/pink wire at transmission switch: 12v in Neutral, ~11.36 in Reverse
3. Voltage at Black/pink wire in cab near fuse panel: 12v in Neutral, ~11.36 in Reverse

#2 is why I originally posted here. According to the Chilton diagram, it's Pink/Orange from fuse 26 to Manual Backup Lamp switch, and nothing but Black/pink coming out of that switch, all the way to the bulbs. Why in the world would I have 12v in Neutral with a slight drop in voltage in Reverse?

But, #1 shows that at the lights, it's functioning as it is supposed to - simple Off/On.

Anyways, I hope I've answered your questions - and that you might be less confused than me.
 

RobbieD

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But I still can't get reverse gear to trigger the camera...
Are you running LED bulbs for reverse lights?

If so, put the incandescent bulbs back in just for testing, and then see if the camera starts working like it should.
 

pjtoledo

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my Chiltons has the same info as yours, however, my 2005 factory manual
shows VT/OG feeding power to the reversing switch on the transmission from fuse F2.20
from the switch to the lamps is the BK/PK wire
connector C311 is a big square under the cab.
EDIT: c311 is an 8 pin round connector, attached to the frame on mine.

I'm also installing a BU camera.

2024-05-22 22.29.24.jpg
 
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pjtoledo

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EDIT: any BK/PK wire in the cab is a different circuit. the BK/PK for the backup lights exists only under the truck.
it goes from the switch directly to the lights.

can you post a pic of the BK/PK wire near the fuse panel?

if you remove the backup bulbs the circuit should be open from the BK/PK to ground.
with the connector removed from the transmission, on the BK/PK wire
you should show the resistance of the bulbs when installed, and infinite when bulbs are removed.
the other wire should be 12v to ground with key on, bulbs or no bulbs.
 
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captainkirk

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Are you running LED bulbs for reverse lights?

If so, put the incandescent bulbs back in just for testing, and then see if the camera starts working like it should.
GREAT question, but no - I've still got the incandescents. Thank you for the thought and suggestion!
 
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captainkirk

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can you post a pic of the BK/PK wire near the fuse panel?
I will do that in a couple days - thank you so much for the add'l info and troubleshooting steps. Best wishes on your cam install; do let us know how it goes...
 

2011Supercab

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I think what's going on is the switch at the transmission is a ground switch.

Power from the fuse box to the light then from the light to the switch which grounds the circuit when put in reverse,

If that's the case, I have no idea of how to activate the camera by using the backup lights.
 

RobbieD

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Although the schematic in post #5 shows a positive-switching circuit, if it is a ground-switching circuit in your truck you can add a relay to reverse the polarity to switch the camera on.

I'm OK with the older horse-drawn trucks, but I'm just not familiar with the newer trucks.
 

captainkirk

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can you post a pic of the BK/PK wire near the fuse panel?
First off, the promised pic of the wiring at the panel. Below that, an apology for getting some of my wires crossed...er, colors crossed?

Legend for the photo:
Top to bottom, 1-4:
Wire #1 is in the "middle" wiring connector. I call it "middle" because there is a smaller one above it, but it is behind the panel so far, you'd have to remove screws from plastic to disconnect it.
Wires 2-4 are in the bottom wiring connector.
Wires 1 and 3 give 12v no matter which position the gearshift is in.
Wires 2 and 4 give no voltage.
In this close-up, even I can see that wire #3 is brown - read on for my mea culpa!
IMG_20240603_192141063.jpg

More time has elapsed than I intended, and that's because my wipers stopped working. Slightly more important than getting the backup cam fully operational.
During my troubleshooting of the wipers, the batteries on my headlamp died. Tonight, with full-strength batteries, I realized that what I thought was a Black/Pink wire going into my transmission was actually neither color!
Also , I wasn't able to locate any connectors under my cab that looked like the C311.

On the wipers, I've already done the basics - check fuse, clean switch on steering column, look for loose connectors, and swap relay 45A w/45B. They'd been behaving badly for years and finally gave up the ghost. Taking it in to a local mechanic for that on Wednesday. If he has any suggestions about the reverse wire, I'll post here.

Thanks all for trying to help!
 

captainkirk

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I think what's going on is the switch at the transmission is a ground switch.

Power from the fuse box to the light then from the light to the switch which grounds the circuit when put in reverse,

If that's the case, I have no idea of how to activate the camera by using the backup lights.
At least I figured out I was trying to tap the wrong wire that was coming out of the trans. It wasn't Black/Pink at all - sorry about that! But I am fairly certain that what I was tapping into is the reverse lamp switch, based on my completely scientific assessment of online pics from AutoZone...
 

captainkirk

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I got it working, finally! I thought I'd update here with "Lessons Learned" for any future info-seekers:

1. (Unrelated but since I mentioned this above) The wipers turned out to be some sort of issue on the BACK SIDE of the fuse panel (the one in the kick panel). The mechanic fixed it - for now, he says.

2. Even after the repair, I *still* couldn't get a Black/Pink wire to give me 12v only when in reverse. The next tech I spoke to at Crutchfield informed me that sometimes, the factories will use non-standard wire in the looms just because they ran out, and they wanted to keep the line moving. So he told me to stop hunting for one in the cab, and just run a long one back to the taillight where I knew it worked.

Problem solved!

Hitting yourself in the head with a hammer feels so good, but only when you stop...

And I love the camera - it fits under my tailgate handle just fine and shows exactly what I need to see, especially at night.

It's an iBeam surface-mount (Model TE-CLED from Best Buy).

Again, thank you to @RobbieD @pjtoledo @2011Supercab !
 

pjtoledo

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I spliced mine right at the switch on the transmission. the colors were correct., it's a 2005 2wd.
it's turning out to be quite a fiasco.
I was getting erratic readings when first started, got frustrated and gave up for the night, put it all
back together and checked the backup lights. nope, no way, they ain't lit.
next day opened up the light sockets, only slight corrosion. cleaned it up, tested bulbs, have ground, but no voltage.
back under the truck, (I'm 71 and have back pain) pulling and checking wires. noticed the female pins in the
harness didn't exactly match up, thought the power pin was pushing out so I pushed it back in.
got the voltage at the connector, put it back on, nothing.
turns out the female pin was broken, I pulled the tube part right out of the connector, the wire crimp stayed in.
cut the connector off, nothing I had was close.
quick trip to closest parts store, nope, nothing like that one.

this tube is about a quarter inch long, hole for the pin is 2mm or about .079"
grabbed my smallest soldering iron and managed to attach a wire to it, pulled it thru the connector.
back under and spliced the camera power, fed the wire along the harness and into the cab right behind the seat.
the 6 feet of wire I attached was too short. I'll make it up with the harness that came with the camera,,,,,when I find it :annoyed:
for now I'm still using the power plug adapter, hit the big red button and it works. I don't want to cut those wires, yet.
backup lights work too.
while I was checking things out at the rear noticed a license light was out. corroded socket, going to order one.

by the way, that black/pink wire STARTS at the switch on the tranny and goes along the frame and directly to the rear.
it is not in the cab.
only the power feed to the switch is in the cab, and it's always hot when the key is ON. book shows it's VT/OG
which matches the feed at my switch.
 

pjtoledo

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went back and edited a couple posts to clear up some confusion.
 

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