Trailer Lighting and Storage Mods

Panik · Dec 6, 2013

So not too long ago I purchased a 18' (16' + 2' dovetail) P&T 7K car hauler (2k trailer weight, 5K capacity) with brakes on both axles. It was purchased to haul our BX2360 as well as for general purpose hauling.

For the little use it has seen so far it works well for its purchased purpose. It has a little more cross frame flex than I would necessarily like, but that issue as well as possibly reinforcing the cross members are a potential project for down the road....... weight dependent.

In any case one of things I did not like was the factory wiring job - scotch lock and wire wrapped around axle frames. One of the first things I have done is to start to re-work the wiring using junction boxes and heavier gauge SJOOW wire. I also have added LED rear ID lights, as well as side and front marker lights. Unfortunately I am getting in a bit over my head and could used some advice on a couple of points:

Please forgive me if the questions are goofy I've been doing so much reading that things are starting to run together.

I would like to have the side marker lights function as turn indicator lights however I am not sure I completely understand how to do this. They trailer will be connected to a jeep commander with 7 way plug. Can I just simply run the left and right middle markers off of the left and right turn wires? If so will they also come on with the brake lights? I am okay with this if it happens for simplicity sakes - I know there is a relay based solution for that issue, but I don't want to attempt it at the moment unless necessary.

Also given that I am using LED lights for the markers and dual filaments for the rear brake and turn indicators do I need some form of converter to slow the flash rate of the LED's?

2) I am adding a storage box onto the front of the trailer because I am really tired of having to throw chains, tie downs, etc into the back of the jeep. Yes, I know first world woes

. Anyways the tongue on the trailer is pretty short so I do not think I will be able to mount the box in front of the deck for fear of bashing up the jeep. I could be wrong on this and need to test things. As well I don't want to lose deck space so...... Does anyone see any issues with mounting the box on the front rail of the trailer and building a small angle iron frame to support it?

3) Lurking around Pirate4x4 I saw where someone had run wiring so that when they had a vehicle on their trailer they could plug the towed vehicle into the trailer wiring harness and the run the brake and turn lights via the vehicle doing the towing. I would love to do this with my tractor. I believe the individual who did this used diodes (purchased from and RV) to prevent issues with current going the wrong direction. It seem like a pretty simple mod - is there anything I am missing?

aczlan · Dec 6, 2013

Panik said:
I would like to have the side marker lights function as turn indicator lights however I am not sure I completely understand how to do this. They trailer will be connected to a jeep commander with 7 way plug. Can I just simply run the left and right middle markers off of the left and right turn wires? If so will they also come on with the brake lights? I am okay with this if it happens for simplicity sakes - I know there is a relay based solution for that issue, but I don't want to attempt it at the moment unless necessary.

If you do that,the side markers wont come on unless the turn or brake lights are on.
Will your rear lights be LEDs, or incandascents? If you have incandescents, you can wire the markers to turn off when the brake or turn lights come on
Not unless you have incandescent brake lights somewhere in the system (see Volvo 740/940 Side Marker Lamp Wiring for how to wire them in that case ) OR you run wires for BOTH marker and turn signal lights, then put a resistor on the marker lights (just for the fenders) so that they run as seen below:

Adjusting the resistor to be (for example) 9 volts when the running lights are on will give you 9 volts for the running lights and 11-12 volts for the brake/turn lights.

Panik said:
Also given that I am using LED lights for the markers and dual filaments for the rear brake and turn indicators do I need some form of converter to slow the flash rate of the LED's?

Shouldn't as in most cases that is controlled by the turn signals on the tow vehicle. Worst case, you will need a electronic flasher (uses a electronic circuit vs a bi-metal strip to turn power on/off).

Panik said:
3) Lurking around Pirate4x4 I saw where someone had run wiring so that when they had a vehicle on their trailer they could plug the towed vehicle into the trailer wiring harness and the run the brake and turn lights via the vehicle doing the towing. I would love to do this with my tractor. I believe the individual who did this used diodes (purchased from and RV) to prevent issues with current going the wrong direction. It seem like a pretty simple mod - is there anything I am missing?

I am not sure that you would need diodes as long as the towed vehicle (and its lights) are off, but I could be wrong on that.

Aaron Z

msb1766 · Dec 6, 2013

I have a similar trailer this it what I got for the tongue box:
Buyers Trailer Tongue Toolbox - Tractor Supply Co.

bandaidmd · Dec 6, 2013

put decent lights on the trailer and forget trying to light up what your hauling its not needed but if you want it for the cool factor some sort of diodes will be needed.
To have your marker lights also be turn signals they need to be swapped out for duel filliment lights , they have them at truck stops and other places truck lighting is sold.
you won't need dummy loads on the trailer leds the tow vehicle will provide enough load for the flasher to work properly.
Did you put a 6 wire to 4 wire converter on the jeep or run separate wires for turn signals.

Panik · Dec 6, 2013

Hey guys thanks for the quick replies.

Aaron - It's pretty cool you brought up volvo's. I learned how to drive on a 240 wagon and drove until it had about 275,000 miles on it. It was awesome as a vehicle for a high school and college student because I could haul everything and everyone. It also had that its so goofy it's cool factor going on :cool2:

Bandaidmd - Regarding using my tractor's turn lights while it's being towed.... Yup, it is mostly for the cool/fun factor. Although 10 years from now I may smack myself and look at it the same way you might when you see 20,000 chicken lights on a big rig.

Also about a year ago I went from being a career zoo keeper (15 years) to being a stay at home dad in a new town taking care of a new born daughter, two young high functioning autistic boys (3 and 5) as well as my mom who is slowly declining mentally and physically. :confused2: I'm used to working with my hands, and doing a lot of physical problem solving. Taking care of family is very rewarding, however getting lost for an hour so here and there on projects like this trailer keep me sane. They satisfy that learning and problem solving part of my brain and give me time away from my current "job". Sorry... That's not meant as a vent at anyone, just kinda needed to get it off my chest for personal reasons.

Anyways the other reason for turning this into an episode of "Pimp My Ride - Trailer Edition" is that the trailer's rear lights are awful low. As in I am not sure if they hit minimum legal height. Unfortunately there is not a real easy way to change this without putting the rear lights in a location where they might be cleaned off by loading and unloading material. So having functioning lights on the tractor while in transit is kinda, a semi sorta legitimate excuse for what I am trying to do.

In answer to the questions posed, I do currently have incandescent brake and turn lights at the rear of the trailer. However, I do plan on changing this sometime down the road when I find a set of LED rear lights I like that fit the trailer. Also the trailer is being wired as a full 7 wire set up as I am planning on adding back up lights and possibly a breakaway setup. In all honesty I am planning on adding additional, switched, back up lights to the Jeep as the stock ones don't do a frakking thing, and I am scared I'm going to back over the dogs one day. The jeep has a 7 blade rv receptacle - I am assuming it is fully wired, if it isn't it will be by the time this is done.

I think the idea of running the two side fender markers off both the turn wires and the marker wire with a resistor is pretty awesome. As these are wired into their own junction box it should be easy to accommodate. Is there something purpose made for this type of thing, or should I be looking at possibly wiring up a linear potentiometer for each marker so that I can adjust the contrast between the marker function and indicator blinking?

Bandaidmd can you explain your statement about the dummy loads? Is that in reference to my question about needing to slow the flasher rate on the LED's? In regards to the diodes for the tractor I was planning on picking up something like this from the local RV store:

MSB1776 - I looked at a aluminum version of what you have and while it does eliminate the issue of jack knifing the jeep into the storage box I wanted something a little larger, both for storage and so that I can accommodate running my primary wiring junction box inside the storage box for a cleaner look. Thank you for the suggestion tho.

Again my thanks for all of the assistance. I will post pictures as things come together.

Xfaxman · Dec 7, 2013

aczlan said:
-------------------OR you run wires for BOTH marker and turn signal lights, then put a resistor on the marker lights (just for the fenders) so that they run as seen below:
View attachment 348913
Adjusting the resistor to be (for example) 9 volts when the running lights are on will give you 9 volts for the running lights and 11-12 volts for the brake/turn lights.

-------------------------------------------

Aaron Z

Aaron, have you tried this with a LED marker light? I know it will work with incandescent lights, not sure about LEDs.

The LED in my rechargeable flashlight doesn't dim when the battery gets low, it just goes off.

The best way would be to use a LED side marker/ turn lamp.

It has separate wires for the two functions.

Panik · Dec 7, 2013

Xfaxman if I had not already cut holes in the fenders to recess the side markers I would be all over the two function LED lamp idea. I just haven't been able to find a 2" round two function led light, although I am not done looking. Originally it wasn't going to be an issue as they were just going to be generic side markers (so much for thinking things out ahead of time

)

In any case from looking at stuff on the instructables website I know it is possible to regulate basic LED light brightness with resistors. However, I also know that in cases such as some flashlights a driver circuit regulates the LED output to a constant level until battery levels drop to a certain level at which point the LED stops emitting light. What I don't know is what type of circuitry is included with basic side marker LED's

Regardless it should be relatively easy to experiment. The junction boxes I used have terminal strips in them so it should be easy to change wiring configurations:

On a slightly cooler note I got my brake controller installed in a location that is easy to reach and doesn't require me bashing my knees on it under the dash:

aczlan · Dec 7, 2013

Xfaxman said:
Aaron, have you tried this with a LED marker light? I know it will work with incandescent lights, not sure about LEDs.

The LED in my rechargeable flashlight doesn't dim when the battery gets low, it just goes off.

The best way would be to use a LED side marker/ turn lamp.
View attachment 349008
It has separate wires for the two functions.

I have done it with this lamp: Clear LED Red Light 1x2 5" Oval Surface 2 Diode Trailer Truck Marker CLEARANCE | eBay and it worked well for the ~10 mins I tried it.
If you could get a small dual function marker that would be great.

Aaron Z

bandaidmd · Dec 7, 2013

Panik said:
Hey guys thanks for the quick replies.

Aaron - It's pretty cool you brought up volvo's. I learned how to drive on a 240 wagon and drove until it had about 275,000 miles on it. It was awesome as a vehicle for a high school and college student because I could haul everything and everyone. It also had that its so goofy it's cool factor going on :cool2:

Bandaidmd - Regarding using my tractor's turn lights while it's being towed.... Yup, it is mostly for the cool/fun factor. Although 10 years from now I may smack myself and look at it the same way you might when you see 20,000 chicken lights on a big rig.

Also about a year ago I went from being a career zoo keeper (15 years) to being a stay at home dad in a new town taking care of a new born daughter, two young high functioning autistic boys (3 and 5) as well as my mom who is slowly declining mentally and physically. :confused2: I'm used to working with my hands, and doing a lot of physical problem solving. Taking care of family is very rewarding, however getting lost for an hour so here and there on projects like this trailer keep me sane. They satisfy that learning and problem solving part of my brain and give me time away from my current "job". Sorry... That's not meant as a vent at anyone, just kinda needed to get it off my chest for personal reasons.

Anyways the other reason for turning this into an episode of "Pimp My Ride - Trailer Edition" is that the trailer's rear lights are awful low. As in I am not sure if they hit minimum legal height. Unfortunately there is not a real easy way to change this without putting the rear lights in a location where they might be cleaned off by loading and unloading material. So having functioning lights on the tractor while in transit is kinda, a semi sorta legitimate excuse for what I am trying to do.

In answer to the questions posed, I do currently have incandescent brake and turn lights at the rear of the trailer. However, I do plan on changing this sometime down the road when I find a set of LED rear lights I like that fit the trailer. Also the trailer is being wired as a full 7 wire set up as I am planning on adding back up lights and possibly a breakaway setup. In all honesty I am planning on adding additional, switched, back up lights to the Jeep as the stock ones don't do a frakking thing, and I am scared I'm going to back over the dogs one day. The jeep has a 7 blade rv receptacle - I am assuming it is fully wired, if it isn't it will be by the time this is done.

I think the idea of running the two side fender markers off both the turn wires and the marker wire with a resistor is pretty awesome. As these are wired into their own junction box it should be easy to accommodate. Is there something purpose made for this type of thing, or should I be looking at possibly wiring up a linear potentiometer for each marker so that I can adjust the contrast between the marker function and indicator blinking?

Bandaidmd can you explain your statement about the dummy loads? Is that in reference to my question about needing to slow the flasher rate on the LED's? In regards to the diodes for the tractor I was planning on picking up something like this from the local RV store:

<img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=348944"/>

MSB1776 - I looked at a aluminum version of what you have and while it does eliminate the issue of jack knifing the jeep into the storage box I wanted something a little larger, both for storage and so that I can accommodate running my primary wiring junction box inside the storage box for a cleaner look. Thank you for the suggestion tho.

Again my thanks for all of the assistance. I will post pictures as things come together.

Dummy load would be needed if you had all led lights on tow and towed. There wouldn't be enough draw on the system to activate the flasher.
your jeep has seperate from the brake lights yellow turn signals ,correct?
If so you need to convert that down to the old style combined brake and turn. Your 7 wire rv plug is designed for that style not the newer separate turn sig.
You trailer plug has hot, grd, brake light/rt, brake light/lt, backup, trailer brakes and lights.