Brake Lights, Turn signal lights, marker lights, oh my!

[glamourpets]

I recently bought a pair of side new marker lights. These lights contain both a turn signal and a marker light in one unit. I am now pondering how to wire them. The rear brake light and turn signal light are one in the same. I was originally planning to wire these lights in paralel with the rear turn signals. For the marker side of the light, this should work out fine. The problem is that these side turn signals will go on with both brake application and turn signal. How do I fix this?

I could run more wires from the tow vehicle, but I would rather stick with the standard 7 way connector.

Does anyone have a good solution to my problem?

PS. Since all exterior lights are LED, amp draw is a minimal concern.

[Raz]

Since the turn signal/brake lights are combined in the tow vehicle, that's where you would have to go to separate them. On newer vehicles these signals need to be buffered (electronically isolated) to prevent loading (effecting) the existing vehicle lights. This is what the light converters do but I have not seen one with separate brake and turn signal wires?? On older vehicles you can just tap into the tail lights. You then need to reassign the wires on your 7 way plug/socket to left turn, right turn, and use the auxiliary for the brakes. Finally, you need to have separate wires and lamps for brakes and turn signals on the trailer. I am not sure I would go to the trouble but it is certainly doable. Raz

[glamourpets]

Originally Posted by P. Raz

Since the turn signal/brake lights are combined in the tow vehicle, that's where you would have to go to separate them. Raz

These turn signal/markers seemed like a good idea in the store, but I didn't think through the wiring. I really would prefer to stay with a standard connection at the tow vehicle. If you start down this path, you have to customize any time your tow vehicle may change.

I was mentally playing with some sort of relay arrangement. If both rear brake lights are on, the side turn signal light should be off. This is the sort of direction I was going... Thoughts?

Derek

[SilverGhost]

I have a suggestion for you. They make a diode box for third brake lights on pickup trucks and bed toppers so you can pull the brake signal without it flashing with the turn signals. Probably similar thing for the LED strip some people put under the tail gate on their pick ups.

I wonder if the companies that make those diode boxes also make one that does what you want? Or maybe if we study those boxes we can build one ourselves?

Jason

[SilverGhost]

Originally Posted by glamourpets

These turn signal/markers seemed like a good idea in the store, but I didn't think through the wiring. I really would prefer to stay with a standard connection at the tow vehicle. If you start down this path, you have to customize any time your tow vehicle may change.

I was mentally playing with some sort of relay arrangement. If both rear brake lights are on, the side turn signal light should be off. This is the sort of direction I was going... Thoughts?

Derek

So what happens when your hazard lights are on? I was thinking of something similar, but realized there would have to be a little more "brains" to tell the difference between solid signal from brakes and turn signals or hazards.

Jason

[Thomas G.]

You can use this adapter. It separates the brake and turn signal power. I use it on my UHaul so I can have separate amber turn signals, even though the TV powers the brake and turn signals together.

[glamourpets]

Originally Posted by SilverGhost

So what happens when your hazard lights are on? I was thinking of something similar, but realized there would have to be a little more "brains" to tell the difference between solid signal from brakes and turn signals or hazards.

Jason

Four way hazards do complicate matters. From the side you only see half of the lights anyway. If these lights work only in turn signal but not 4 way $ode, I would be happy.

Hopefully the electrical wizards amongst us have more ideas to offer.

Derek

[SilverGhost]

That was what I was thinking about, Thomas. I guess since you already have brake/turn on the back flashing then it wouldn't matter much if the side marker/turn signal were not flashing.

To the OP, I think you have your solution. Thank you Thomas

Jason

[Raz]

Originally Posted by Thomas G.

You can use this adapter. It separates the brake and turn signal power. I use it on my UHaul so I can have separate amber turn signals, even though the TV powers the brake and turn signals together.

I assumed those converters were for developing a third brake light and that the turn signal/brake lines operated the same. Apparently there is more going on in that converter than I thought. To keep the turn signal off when the brake light is on requires sensing the duty cycle of the signal. That is, the converter must figure out if the voltage present is due to the brake or the turn signal. I would be curious how they did that. Raz

[Frederick L. Simson]

I have an extra set of amber side marker lights on the front sides of the Fiber Stream wired to the brake/turn signal circuits.

Originally Posted by glamourpets

I was mentally playing with some sort of relay arrangement. If both rear brake lights are on, the side turn signal light should be off. This is the sort of direction I was going... Thoughts?
Derek

I tried this with the relays wired into the extra amber side markers that I connected to the stop/turn circuits. When I signaled for a turn, the extra light flashed on the appropriate side. (Check) When I stepped on the brake, the rear brake lights worked and the extra amber turn signals stayed off. (Check) But when I signaled for a turn AND stepped on the brake, the flashing signal went to the opposite side of the trailer! If I signaled for a left turn, the LEFT extra amber side marker flashed until the brakes were applied, when the RIGHT extra amber side marker flashed instead until I lifted my foot off of the brake pedal and the flashing returned to the LEFT extra amber side marker light. (NOT good) I removed the relays and they're in a drawer in my workshop.

Originally Posted by Thomas G.

You can use this adapter.

I tried this after my relay experiment failed. It did not work for the added amber turn signals; it merely opened the circuit and did not allow them to come on at all, ever.

I disconnected it, and now accept that the extra amber side marker lights work in the same way as the tail/stop/turn lights.

[glamourpets]

Originally Posted by Thomas G.

You can use this adapter. It separates the brake and turn signal power. I use it on my UHaul so I can have separate amber turn signals, even though the TV powers the brake and turn signals together.

Thomas, what was your basic wiring diagram for your trailer with this adapter?

Frederic claims the adapter didnn't work. It MIGHT be an issue of incorrect wiring. It might also be that his particular adapter was a dud, but the design is basically sound. Or maybe these units don't work in this application.

Is anyone else using this unit successfully?

Also, are these units LED friendly? Some relays are happier with the resistance they get from traditional bulbs.

Derek

PS. No offense intended. I'm just trying to push past two opposing views on the same product.

[Frederick L. Simson]

Originally Posted by glamourpets

Frederick claims the adapter didn't work. It MIGHT be an issue of incorrect wiring. It might also be that his particular adapter was a dud, but the design is basically sound.

PS. No offense intended.

I included my experience here to find out if I did something wrong and compare notes with Thomas who seemed to be successful. The unit is still installed in the trailer, the spade lugs I used to make connections are merely unplugged from it.

[Thomas G.]

Originally Posted by glamourpets

Thomas, what was your basic wiring diagram for your trailer with this adapter?..........

Input

• One left turn / brake wire is one input
• One right turn brake / is the second input.

Output

• One wire goes to the brake lights.
• One wire goes to the left turn signal
• One wire goes to the right turn signal

The running lights wiring bypasses by the module.
Ground wire bypasses the module

All I can say is that it works for me. I think the module's internal circuit senses when both turn signal wires are powered and diverts the power to the brake lights. When just one side is powered (for turn signal) it passes the power to the appropriate light. When you step on the brake, the module clicks, indicating a mechanical relay inside. I tried to think of a simple logic circuit to duplicate this function using a couple of relays, but gave up and paid the $20 for the module. I have standard incandescent light bulbs. Not sure what effect LEDs would have.

[glamourpets]

Found installation instructions for this product:

Trailer Hitch Instructions For DrawTite, Reese, Hidden Hitch & More - etrailer.com

Its really not much more than a wiring diagram.

Here is the etrailer link for the original product.

http://www.etrailer.com/Accessories-...rt/C56196.html

[glamourpets]

It appears that Etrailer recommends that you also should use the above listed product with the following part. I am not sure I entirely understand why, but maybe this is where Frederic wend wrong? Thoughts?

Tail Light Isolating Diode System with Wiring Harness Hopkins Tow Bar Wiring 38955

...or maybe this is just a towbar issue that only comes up when you pull a car ?

[Thomas G.]

Originally Posted by glamourpets

It appears that Etrailer recommends that you also should use the above listed product with the following part. I am not sure I entirely understand why, but maybe this is where Frederic wend wrong? Thoughts?

Tail Light Isolating Diode System with Wiring Harness Hopkins Tow Bar Wiring 38955

...or maybe this is just a towbar issue that only comes up when you pull a car ?

I think that the diodes isolate the two vehicles electrical systems. For a trailer, just the adapter module should do the trick.

[Frederick L. Simson]

Originally Posted by glamourpets

Frederic claims the adapter didn't work. It MIGHT be an issue of incorrect wiring.

Is anyone else using this unit successfully?

If there's a screwed up way to do something, I'll find it first!

Originally Posted by Thomas G.

Output

• One wire goes to the brake lights.
• One wire goes to the left turn signal
• One wire goes to the right turn signal

I think the module's internal circuit senses when both turn signal wires are powered and diverts the power to the brake lights. When just one side is powered (for turn signal) it passes the power to the appropriate light. When you step on the brake, the module clicks, indicating a mechanical relay inside.

All I cared about were the turn signals. I never connected an actual light to the output brake wire. Once I added a concealed brake light near the terminal strip inside, the turn signals work perfectly!

[Thomas G.]

Originally Posted by Frederick L. Simson

If there's a screwed up way to do something, I'll find it first!


All I cared about were the turn signals. I never connected an actual light to the output brake wire. Once I added a concealed brake light near the terminal strip inside, the turn signals work perfectly!

Great news. I wouldn't feel bad about it, as I don't recall the instructions saying that all three wires need to be connected for it to function. And it is a black box, so who knows the exact logic of the circuit?

[Raz]

I'm curious, is there a delay between the time the tow vehicle turn signal starts to work and the trailer turn signal starts to work? Raz

[Frederick L. Simson]

Originally Posted by P. Raz

I'm curious, is there a delay between the time the tow vehicle turn signal starts to work and the trailer turn signal starts to work? Raz

They appear to be simultaneous.