Back up camera glare from license plate lights

[Mr._Bill]

I finally got my harness installed today. It does help. The biggest problem was getting the connectors apart without breaking anything.

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[OHJeeper]

Thank you for the info but these are already known.

Can you share 4 way connector details?

You mentioned the driver side is 4 way?

Thanks!

The 4-way connector is in the section "License Plate Lamp Harness" in my post - MOLEX 34900-4120 and 34899-4080.

I thought @ShadowsPapa posted the pinouts previously. If I am mistaken, I'll post those as well.

 

[OHJeeper]

There are only 2 pins used in the 4-way connector (1 and 4), you just interrupt the connection to the white/blue banded wire to turn off the license lamps. The black is ground.

 

[ShadowsPapa]

The 4-way connector is in the section "License Plate Lamp Harness" in my post - MOLEX 34900-4120 and 34899-4080.

I thought @ShadowsPapa posted the pinouts previously. If I am mistaken, I'll post those as well.

I really need to organize my files - I found the tail light connector info, but didn't find my PDF and JPG files for the other.

 

[DailyDrivenTJ]

There are only 2 pins used in the 4-way connector (1 and 4), you just interrupt the connection to the white/blue banded wire to turn off the license lamps. The black is ground.

Pin 1 and 4, it is! Thanks!

Just to recap, driver side license plate light has the 4 way molex connector of which it uses 2 pins.

These 2 pins will provide power and ground for the relay, and reverse light circuit will provide the trigger for the NC relay.

Does everyone agree on this?

 

[ShadowsPapa]

Pin 1 and 4, it is! Thanks!

Just to recap, driver side license plate light has the 4 way molex connector of which it uses 2 pins.

These 2 pins will provide power and ground for the relay, and reverse light circuit will provide the trigger for the NC relay.

Does everyone agree on this?

Use the connector on top of the left frame rail, near the spare tire heat shield. It's secured on top of the left frame rail.

I don't use the connector at the license plate light itself, but the one on the frame.
This keeps your wiring short and away from the bumper. The wires can exit the space behind the tail light and go almost straight down and then forward a bit to the top of the frame rail.

Run your hand along the last few inches of the top of the left frame rail, especially near the spare tire heat shield. You'll find the connector to use up there.

 

[OHJeeper]

Just to recap, driver side license plate light has the 4 way molex connector of which it uses 2 pins.

To be clear, this 4-pin connector is not at the license light, it's a foot or so under the bed at the driver's side frame rail where it meets the spare tire mount. It continues on to the actual license lamp connector which is a 2-pin connector.

These 2 pins will provide power and ground for the relay,

This is not how I wired it. I used the 12V connection in the tail lamp harness (Pin 5) for relay power, and Pin 6 for ground - I only ran one wire from the license lamp 4-pin connector to the relay for the NC connection (the blue/white wire) - that part we agree on. Well, it's actually 2 wires - one to the relay and one from the relay to be technical. I hope that makes sense...

 

[ShadowsPapa]

To be clear, this 4-pin connector is not at the license light, it's a foot or so under the bed at the driver's side frame rail where it meets the spare tire mount. It continues on to the actual license lamp connector which is a 2-pin connector.


This is not how I wired it. I used the 12V connection in the tail lamp harness (Pin 5) for relay power, and Pin 6 for ground - I only ran one wire from the license lamp 4-pin connector to the relay for the NC connection (the blue/white wire) - that part we agree on. Well, it's actually 2 wires - one to the relay and one from the relay to be technical. I hope that makes sense...

You did as I've written out.

You are breaking that white with blue tracer and putting the relay terminals 30 and 87A in the circuit. When the relay coil is energized by power flow to 85 and 86, then it opens the switch which is normally closed using 30 and 87A
It can be a really small relay as the LED plate lamps take very little power.
30 and 87A are normally closed contacts, energize the coil with power from the backup lights, they open, killing the license plate lamps.

 

[OHJeeper]

You did as I've written out.

You are breaking that white with blue tracer and putting the relay terminals 30 and 87A in the circuit. When the relay coil is energized by power flow to 85 and 86, then it opens the switch which is normally closed using 30 and 87A
It can be a really small relay as the LED plate lamps take very little power.
30 and 87A are normally closed contacts, energize the coil with power from the backup lights, they open, killing the license plate lamps.

Yes, exactly how I did it! Thanks for drawing that out.

 

[DailyDrivenTJ]

@ShadowsPapa @OHJeeper

Thanks yall. This will make my job much easier.

 

[Gatorized]

You did as I've written out.

You are breaking that white with blue tracer and putting the relay terminals 30 and 87A in the circuit. When the relay coil is energized by power flow to 85 and 86, then it opens the switch which is normally closed using 30 and 87A
It can be a really small relay as the LED plate lamps take very little power.
30 and 87A are normally closed contacts, energize the coil with power from the backup lights, they open, killing the license plate lamps.

87a/30 becomes integral to the license plate light - when the reverse lights are energized, the relay breaks the license plate circuit turning off that light. Does energizing the relay through the 85/86 path have to go from the reverse light to ground or can it be put in line with pin 5 only (pin 5 male connector to 85, 86 to pin 5 female connector)? Is there an advantage/disadvantage either way?

 

[Ferg]

Tazer can supposedly fix that. I’ll know later this month.

I does, and it's wonderful!

 

[ShadowsPapa]

87a/30 becomes integral to the license plate light - when the reverse lights are energized, the relay breaks the license plate circuit turning off that light. Does energizing the relay through the 85/86 path have to go from the reverse light to ground or can it be put in line with pin 5 only (pin 5 male connector to 85, 86 to pin 5 female connector)? Is there an advantage/disadvantage either way?

I prefer to just "tap" instead of putting a coil inline to the feed of the factory backup light.
Depending on the relay's coil - resistance and so on, it might drop the voltage enough to cause problems with the factory backup light. Just a thought.

Also - when you cut current through a coil there's a reverse current induced in the coil - not sure what effect that would have on the BCM.
I can't see any advantage running the relay's coil inline with the feed to the backup light.
You run two wires either way.

For me, it's easy to run 12 wires straight through female to male, and then "tap" the relay coil feed and ground to the wires at pins 5 and 6.
It's really just as simple either way but I prefer to not put a coil inline with the feed.

 

[DailyDrivenTJ]

87a/30 becomes integral to the license plate light - when the reverse lights are energized, the relay breaks the license plate circuit turning off that light. Does energizing the relay through the 85/86 path have to go from the reverse light to ground or can it be put in line with pin 5 only (pin 5 male connector to 85, 86 to pin 5 female connector)? Is there an advantage/disadvantage either way?

I am not sure if I am understanding this question at all..

Are you asking if the trigger can be added in series into reverse circuit?

 

[Gatorized]

I am not sure if I am understanding this question at all..

Are you asking if the trigger can be added in series into reverse circuit?

Exactly - @ShadowsPapa provided a good reason not to - it could compromise the reverse function. Either technique could be used and not compromise the oem wiring by using the modified harness, but using pins 5 & 6 energizes the relay while keeping the reverse circuit unchanged.

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