Aux back up lights working too well?

[Taz6056]

Well I after rereading Jauto98's post on the OS, and looking at schematics online, I was finally able to hook up my aux backup lights. Three way switch, single relay, Fulltime on(direct to battery), OFF, and auto in reverse only. Having trouble with the reverse only(battery off) because when I turned the truck off, I still had power to the lights. I have them wired to the trailer hitch center pin, which I thought was power on, in reverse only, am I mistaken? Does anyone have any ideas on why I am still getting power after the truck is off? With the setup currently I have 2 issues, A, I could have used a simple on/off switch, and B and more importantly I have lost one of the features I was really interested in, which is the ability to know the battery wont be killed because I'm forgetful. Help.

Marc.

 

[Mark20]

Our trailer plugs do not have reverse in them. [Edit - they do.] They can be fed with constant 12V though.

 

[Taz6056]

Then how are the backup lamps fed then? and on a side note, any advice on how to actually grab power from the battery? How are you all doing it? New battery studs, or some kind of big ring terminal? any advice there would be appreciated as well.

 

[kardain]

Our trailer plugs do not have reverse in them. They can be fed with constant 12V though.

According to GM, they do as there is a fuse labeled for it in the rear fuse block.... The center trailer plug pin is cold when reverse lights off, hot when on.

Check the fuse to see if it is still good.

 

[Taz6056]

Fuse is definitely good, I am getting power more times than I want too.

 

[kardain]

Looking at the question and issue, it may be how your switch is wired. How did you wire yours up?

It should be the two outer pins as the source voltage and the center as the output. The output goes to the trigger on the relay. When you flip the switch one way or another, a contact within slides between the output middle pin to one of the sources.

 

[c bausch]

I just wired up my white knight back up light, the middle pin is reverse, if your looking at the trucks connector to the right of the top center is the power, and the ground is 7/8 o'clock pin, I had some issues with min and a few guy were VERY helpful, I believe when your trailer (red wire) ring is connected by your engine fuse box it sends power to your reverse and I think your trailer brake pins but if you didn't have your (red wire) hooker up you still have your 4 pin connector hoookup functions just no reverse but im noone / sorry thought that it was going to be wired to a trailer connector but I also have a 3 way switch on my light reverse /off/worklight on

 

[Mark20]

According to GM, they do as there is a fuse labeled for it in the rear fuse block.... The center trailer plug pin is cold when reverse lights off, hot when on.

Check the fuse to see if it is still good.

I thought only Ford or Dodge ran reverse to the 7 pin connector. I guess I'll pull out the voltmeter this weekend and verify.

 

[c bausch]

My back ups are wired to my seven pin ,also dumb note that I realized last second when I was wireing it up on your weather flap on the conncetor it has a wireing diagram on the out side and it has the center pin as backup

 

[Taz6056]

My wiring goes like this: Center pin of the switch connects to the trigger wire of the relay(85.) Across that at pin 86 runs to ground in the engine bay. Pin 30, is power to the relay coil, that is attached to the battery directly (where both source voltage, or inputs are also wired to the battery) Going to pin 87 which is power down to the lights. I'm not sure if this matters..... but the switch is Radioshack part number 275-711, wired to 2 separate red lights p/n 272-336, each light is wired to one of the source voltages.



Marc.

 

[kardain]

It reads as you have wired it up properly, except one part has me confused...


"where both source voltage, or inputs are also wired to the battery"

You have two wires coming from the battery to the switch? If so, this will not allow them to turn on/off with the reverse lights. One of the inputs will need to come from the reverse light positive wire, as seen below (for your situation, replacing the park light reference with battery).

And some of the wire colors in small print won't match... I snagged this from a Ford forum (I'm at work, so don't have the time to draft up one of these diagrams at the moment)

 

[Mark20]

Checked the Voy & Silverado and both had the reverse pin active when the tranny was in in reverse. Didn't know GM wired that up.

 

[The_Roadie]

GM leaves the brake circuit unwired until you connect a controller to the harness near the driver's left foot. And the "mystery red wire ring lug" is left off to give us something to answer noob's questions about. The other circuits are installed by default.

 

[Mark20]

I've wired a Prodigy controller in and put a nut on the fuse box stud in case I want to set up the 12v to the trailer plug. I leave that disconnected so I don't forget and kill my battery. Did use it once to top off the camper's battery but a 6 cylinder engine makes an expensive charger.

Years ago someone on a camping forum said only Ford or Dodge wired reverse to the trailer plug. All these years I've had a piece of wrong info in my head.

 

[The_Roadie]

Years ago someone on a camping forum said only Ford or Dodge wired reverse to the trailer plug. All these years I've had a piece of wrong info in my head.

One of my mottoes:
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