Tailgate Light Bar From OPT-7 How I Made it Work For The Ranger

[ControlNode]

I for one would like to see a full diagram (schematic) of how this is all wired together. All we have gotten so far is parts. Really want to see how the Tekonsha part is tied in to keep the truck from thinking a trailer is connected.

If I understand the idea, that Tekonsha needs it's own power/ground and such, then it monitors the voltage on the light signal wires of the 4-pin in a manner that does not close the circuit and trigger the "trailer connected" logic. Then using solid state or relays and the it's own power source signals the desired output light.

Well, I just looked at the install manual and I have no idea how it's preventing the feedback to trigger the trailer connected logic as it doesn't have it's own power source.

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[Big Blue]

If I understand the idea, that Tekonsha needs it's own power/ground and such, then it monitors the voltage on the light signal wires of the 4-pin in a manner that does not close the circuit and trigger the "trailer connected" logic. Then using solid state or relays and the it's own power source signals the desired output light.

Well, I just looked at the install manual and I have no idea how it's preventing the feedback to trigger the trailer connected logic as it doesn't have it's own power source.

Right it is intended to take the three wire (brake any turns) setup from the tailights on our trucks and combine it to the two wire (brake/left turn, brake/right turn) used on the 4 wire trailer plug. I'm assuming he is using the 7 to 4 pin adaptor to get a reverse light signal from the trucks 7 pin connector by putting it in between the trucks wiring harness and the 7 pin trailer connector on the truck. This will still be using the outputs from the trailer module in the truck and look like a trailer plugged in.

That's why I want to see a diagram of how it's all plugged together. And if he has the OEM tow package why did he need a 4 to 7 adaptor in the first place as the OEM trailer plug has both the 4 and 7 pin connector on it.

Without a diagram it's all very confusing.

 

[OCL]

That's why I want to see a diagram of how it's all plugged together. And if he has the OEM tow package why did he need a 4 to 7 adaptor in the first place as the OEM trailer plug has both the 4 and 7 pin connector on it.

Without a diagram it's all very confusing.

Why 4-7 pin: Because the OPT-7 light bar comes only with a 4-Pin plus a reverse wire.

Diagram: Contact Tekonsha
https://www.tekonsha.com/

 

[Big Blue]

Why 4-7 pin: Because the OPT-7 light bar comes only with a 4-Pin plus a reverse wire.

Diagram: Contact Tekonsha
https://www.tekonsha.com/

As I said the OEM tow setup has both a 4 pin and 7 pin connection on the back of the truck. Do you not have the OEM tow package?

The Teknosha website will NOT have the connections to the other parts you have said that you used.

 

[OCL]

As I said the OEM tow setup has both a 4 pin and 7 pin connection on the back of the truck. Do you not have the OEM tow package?

The Teknosha website will NOT have the connections to the other parts you have said that you used.

Yes I know the truck does have both 4pin and 7pin: but the 4-pin does NOT have reverse light. And the OPT-7 only came with 4-pin PLUS a white wire for reverse. Hence the need for the 4-pin to 7-pin Adapter to get the reverse light. I wish the OPT-7 light bar came with the 7-pin.

Listen, if you're still skeptical, don't need to get it for your truck.

 

[airline tech]

Yes, the 4-Pin connector does not have the (Reverse Light) signal so you would have to wiretap that circuit to get it - or use the adaptor that has already provided a tapped source for you.

To understand - the only reason for the adaptor is to bypass you having to physically tap into the existing wiring of the truck, so yes if you have the 4/7 connector this is a bit of overkill in a sense but no matter how you get it - for full function of the light bar you must tap the reverse lights

The key part is the module,
Light bars create issues because they are LED and the TRM monitoring (circuit) sees fluctuating current draw from the LED lights

If you think of the module's operation as the (Lumen + TBC) it's the same operating principle.
The internal logic of the module provides a (Constant & Repeatable) draw from the TRM when the lights are operating that makes the TRM happy and it's so small (current wise) it tricks the TRM's circuit that nothing is installed - yes in the end its still drawing current from the TRM but the (Initial) ramp up has been cleaned up and buffered.

The module is just a (Buffer) between the TRM and the Lightbar that is regulating and smoothing out the draw from the lightbar (LED Drivers)

 

[airline tech]

I should point out that this module may not work the same for every light bar and I would need to dive deeper into the matching specifics on the light bar on one that would be the same as direct wiring it - I will say it’s great to see a option here for the finicky TRM

 

[Big Blue]

Yes I know the truck does have both 4pin and 7pin: but the 4-pin does NOT have reverse light. And the OPT-7 only came with 4-pin PLUS a white wire for reverse. Hence the need for the 4-pin to 7-pin Adapter to get the reverse light. I wish the OPT-7 light bar came with the 7-pin.

Listen, if you're still skeptical, don't need to get it for your truck.

OK! Now your getting nasty. Why won't you show us how it is hooked up. You started this about about how you found a way to get this light bar to work without causing the truck to give you alarms. Then you tell us what parts you used. But, you won't show us how it is hooked up, when we asked.

 

[CTYankee]

I'm going to take a swing at this using the parts the OP recommended. I'll use my old shop to do it so we can document the installation for everyone else. The rest of the parts are due in tomorrow and then I'll schedule the install, so it'll be a couple of weeks before it's done. I've always had tailgate lightbars on my trucks so if this will get the job done, I'm all for it.

 

[ControlNode]

To understand - the only reason for the adaptor is to bypass you having to physically tap into the existing wiring of the truck, so yes if you have the 4/7 connector this is a bit of overkill in a sense but no matter how you get it - for full function of the light bar you must tap the reverse lights

But for that reverse tap at least it can be on the wires of the Opt-7 t-harness that is adding the 4 pin instead of on the truck's OE harness. Or buy the Opt-7 t-harness with 4pin+reverse as he stated he used (which is not the amazon image he first shared).

I think I understand the wiring from his description, but feel he could have done a better job of sharing the actually parts he is using, as I pointed out before, mentioned it's all plug and play, but we all know a 4-pin doesn't carry reverse light signal.

Parts:

• Opt-7 t-harness that addes a 4-pin plug plus a loose reverse light signal wire
• Teknosha module (not sure the exact model number) should be as a 4-pin to 4-pin with ground
• the light bar with 4-pin + reverse signal inputs

Wiring:

• Put the opt-7 t-harness inline on the Truck OE harness
• connect the 4-pin form opt-7 t-harness to Teknosha module's input
• ground Teknosha module
• connect light bar's 4-pin to Teknosha's 4-pin output
• Connect the reverse signal from opt-7 t-harness to light bar's reverse signal input.

My idea would be different
Parts:

• Teknosha ZCI™ Zero Contact Interface Universal ModuLite® (119250)
• light bar with 4-pin + reverse signal inputs

Install:

• Install Teknosha module as instructed
• tap reverse signal near 7-pin on the truck, or still get an opt-7 t-harness with reverse output and just use that one wire.
• connect light bar to Teknosha 4-pin output and tapped reverse signal.

 

[airline tech]

Ok I did some research on what triggers the (Trailer Connected) Message
The TRM has a monitoring window of - (500 to 2500 mA) or 0.5 to 2.5 Amps
The primary circuit that is monitored is the Left (Park/Turn)

Compare:
Typical Trailer Bulb -1800 to 2200 mA per bulb or 1.8 to 2.2 amps
OPT 7 Lightbar - 250 mA or 0.25 amps

Now I reflect back on my (BCM circuit checks) and it sends test pulses down the circuit for circuit integrity and wondered - Is the TRM the same?

Yes, it is

Off State Monitoring - No Trailer Connected
Occurs When
1. Key On - start up
2. Lighting Command (Truck Lighting)
3. Periodically (pulse) checks when the can bus is active

Small test pulses are sent down the TRM circuits and the TRM checks the circuits for
Resistance To Ground
Leakage Between Circuits
State change for (presence of connected load)

So, this explains why the Trailer Lighting had a recall early on, the corrosion in the connector
created a path to ground for that test pulse and triggered the -Intermittent (Trailer Connected / Disconnected) message (Pin to Pin or Pin to Ground)


On State Monitoring -Trailer Connected

The TRM measures:
1. The Current Draw
2. The Current Ramping (Behavior)
3. The Voltage Drop


So, for a normal incandescent bulb as long as the wiring is intact, no issues but LEDs have a different operational signature that the TRM is not programmed to monitor, and it mainly has to do with the (filament) in the bulb (Resistance) and current ramps as the filament heats up.
So predictive load signature

For the LEDs and the LED Driver
It regulates the current to the LED lights, and it's a lower and more steady current and they can create feedback paths back into the TRM
Although a steady current about (250 mA) under the 500mA for trailer detection - it's the TRM's test pulse that triggers the (Trailer Connected) message and it creates a temporary voltage spike that pushes it above the minimum (500mA) for detection

This is why the OP was having the issues

I was curious on how the module worked

And I thought I would pass it along

What the Tekonsha Module does and why it helps
It ties to the (Circuit Testing) of the TRM


1. Low Impedance input (Low Current) - when the TRM runs the check it sees only a few mA's about 1 to 5 mAs and treats it as on open circuit (No Trailer Connected - No Load)

2. Internally when the lights are activated it uses that same lighting output the module provides internal switching.

The module reads the vehicle lighting signal using a very high-impedance input that draws only a few milliamps, and that signal activates an internal electronic switch (Power Transistor) that powers the lights through a separate path, so the TRM only sees the sensing current rather than the actual lighting load.

It also separates the circuits and has Diodes installed to prevent any feedback voltage into the TRM

So, to sum it up the TRM provides the Output Signal, and the module takes that signal as an activation signal and then the module actually powers the lights via that (Power Transistor)
and this explains how it can be done without an external power source.

 

[AzScorpion]

OK! Now your getting nasty. Why won't you show us how it is hooked up. You started this about about how you found a way to get this light bar to work without causing the truck to give you alarms. Then you tell us what parts you used. But, you won't show us how it is hooked up, when we asked.

It would be nice to see a few pictures of it installed on his truck. I always wanted one of these lights but the Putco one was way too expensive and this one (by looking at the picture online) doesn't look like it'll clear the tailgate when closed. There's very little room and I can barely get my finger in there but maybe it sits just far enough back? @OCL could you snap a few pictures of yours? One with the tailgate open and another with it closed would be great.

 

[airline tech]

But for that reverse tap at least it can be on the wires of the Opt-7 t-harness that is adding the 4 pin instead of on the truck's OE harness. Or buy the Opt-7 t-harness with 4pin+reverse as he stated he used (which is not the amazon image he first shared).

I think I understand the wiring from his description, but feel he could have done a better job of sharing the actually parts he is using, as I pointed out before, mentioned it's all plug and play, but we all know a 4-pin doesn't carry reverse light signal.

Parts:

• Opt-7 t-harness that addes a 4-pin plug plus a loose reverse light signal wire
• Teknosha module (not sure the exact model number) should be as a 4-pin to 4-pin with ground
• the light bar with 4-pin + reverse signal inputs

Wiring:

• Put the opt-7 t-harness inline on the Truck OE harness
• connect the 4-pin form opt-7 t-harness to Teknosha module's input
• ground Teknosha module
• connect light bar's 4-pin to Teknosha's 4-pin output
• Connect the reverse signal from opt-7 t-harness to light bar's reverse signal input.

My idea would be different
Parts:

• Teknosha ZCI™ Zero Contact Interface Universal ModuLite® (119250)
• light bar with 4-pin + reverse signal inputs

Install:

• Install Teknosha module as instructed
• tap reverse signal near 7-pin on the truck, or still get an opt-7 t-harness with reverse output and just use that one wire.
• connect light bar to Teknosha 4-pin output and tapped reverse signal.

Yes, the wiring is simple -

1. The Tekonsha Module - Has a 4-Pin connector (inputs) and a set of unconnected wires for the outputs to the Lightbar or an optional 4-Pin connector for the connection to the Lightbar

2. Lightbar wired to a 4-Pin connector and if you want the (Reverse) input there is an extra wire.

3. The 4/7 Way adaptor taps into the existing trucks harness giving you an extra 4-Pin plug (in addition to the existing 4 Pin) trucks plug and this also includes a pre spliced wire off of the reverse light power feed on the 7-way plug.

4. The module plugs into the (extra 4-Pin plug) and the modules output connects to the light bar and if you want the reverse lights connect the extra wires together
The Reverse lights are not monitored by the TRM and they are a separate circuit from the BCM

In short, the module is all that is truly needed the adaptor harness makes for a cleaner install and once I dove into the operating aspects of the module it makes sense why it works alongside the TRM

As far as which module (Zero Contact) or the 119178 it would depend on how well the current sensors picked up (current flow) on a low current LED so I am thinking the sensors will need to be around the actual lighting circuits (Taillights) not the TRM outputs as the current sensors will be using the magnetic field created by the lights.

 

[OCL]

OK! Now your getting nasty. Why won't you show us how it is hooked up. You started this about about how you found a way to get this light bar to work without causing the truck to give you alarms. Then you tell us what parts you used. But, you won't show us how it is hooked up, when we asked.

Really? Nasty? Are you always this sensitive?

You're a big boy. You can figure it out using just those pics I sent. Let's start with white wire goes to the white reverse light, Green goes to right turn signal,...c'mon dude! They're color coded. Tekonsha provides the wire color diagram. OPT-7 also provides the diagram. The adapter...well it's just an adapter with male and female ends. The pointy end goes into the holes.... I don't know what else to tell you. If you want it, get the parts, get under your truck and go to work. Don't like it, return it.

 

[OCL]

The module is just a (Buffer) between the TRM and the Lightbar that is regulating and smoothing out the draw from the lightbar (LED Drivers)

100% that's exactly what the Tekonsha unit does. In fact, the Tekonsha website has a short explanation of what it's for. Actually, someone else in this site clued the group in on this unit in another thread, so kudos to him. That was some time ago though so the thread is lost, but can be found using the search.

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