Mid-ship Turn Signal

[Pull Toy]

Driving home from work tonight, almost got taken out by an 18 changing lanes. Got saved by his turn signal about halfway down the trailer!

Cut to the chase... I'm going to add LED turn signals halfway down the length of trailer when the "WEATHER PERMITS" ! (Nor' Easter this weekend!!!)

[Nagrompj]

I like that idea. I've been thinking about it as well. Haven't figured out how to wire it yet as the brake light and the turn signal work together. I don't want the mid-ship light coming on with the brake light.

[hankaye]

Nagrompj, Howdy;

Same light fixture, different wires ... Brake lights and turn signal lamps
will have 2 filiments in them and the brighter is for the brakes.
Do a quick google for trailer wireing and you will see that each (Left & Right),
have different colored wires. Should be easy to splice in and set up your own.

hankaye

PS. This chart should help keep you legal for where and color required.
http://www.nhtsa.gov/cars/rules/stan...tr.html#trlr5a

[chuckster57]

Yes, the rear tail lights have a dual element bulb, but one is used for clearance (running) and the other is brake/turn. If you just splice into the wiring for a dual element side marker light it will illuminate with the brakes.

If you look at the wiring at the 7 way plug, you'll notice that one wire serves the right side brake lamp and turn signal and another wire serves the left side brake lamp and turn signal.

To have side marker lights that serve as marker lights and turn signals with a dual element bulb, will require a separate wire for both sides tied into the TV somewhere upstream where a dedicated turn signal circuit exists. I'm thinking FRONT turn signals. Worth the work? Not in my opinion.

[larry337]

Certainly more is always better but I agree with Chuckster in that it's not worth the effort. Any one beside you can see the tail lights on your tow vehicle. The tail lights on a semi truck are underneath the trailer being towed and not nearly as visible. Not to mention the trailer is 53 feet long. It won't hurt but not worth it in my opinion.

Sent from my SM-G920V using Tapatalk

[bsmith0404]

A dedicated wire from the TV to a turn signal would be nice, but is it really necessary? Does it really matter if the light comes on with the brakes? If the idea is to help notify a car along side of your RV that you are about to turn/change lanes, as long as it works with the turn signal your mission is accomplished. What would it tell the average driver if the light came on when you are braking?....nothing. If they see a "marker Light" suddenly get a little brighter most won't think twice about it, if they see it flashing, they will think turn signal. You don't need to splice into the wires on your trailer to add the light. There is a junction box somewhere on the frame, usually near the pin/hitch. Just run separate wires from the terminal for each turn signal back to "mid-ship" and mount your marker/turn signal with a dual element bulb.

[Pull Toy]

On most SAE /RVIA compliant trailers, the turn signal and brake filament are the same wire x2 (port and starboard). The tow vehicle's circuitry discriminates whether a bulb should flash, or stay lit, just like your truck brake lights. Your trailer is wired to take that signal and apply it to the trailer tail lights the same way. You would just tap into the brake wire for each side and run new leads to the side of the camper.

There is no need for a separate logic circuit unless you have Amber turn signals on the rear of you rig.

[Sprinter274]

Hey pull toy, great idea...I'm in CT too and not looking forward to the storm. Being that the brake/turn are same circuit, a turn signal converter would help

Sent from my SAMSUNG-SM-G870A using Tapatalk

[PerryB]

Originally Posted by hankaye

Nagrompj, Howdy;

Same light fixture, different wires ... Brake lights and turn signal lamps
will have 2 filiments in them and the brighter is for the brakes.
Do a quick google for trailer wireing and you will see that each (Left & Right),
have different colored wires. Should be easy to splice in and set up your own.

hankaye

PS. This chart should help keep you legal for where and color required.
http://www.nhtsa.gov/cars/rules/stan...tr.html#trlr5a

That depends on the tow vehicle. If you have red turn signal lenses in the same housing as the brake lights then you have what is generally considered to be the "American" 2 wire system. Same element for turn and brake. They get split up at the turn signal switch so when you turn, the brake light signal is interrupted to that side. In this case you will get brake lights whether you want them or not. If you have amber turn signals at the rear of your tow vehicle then you have the 3 wire system originally found on Japanese and European cars. They are separate circuits and there will be a diode/converter box somewhere in the vehicle to make it work with your American style trailer. With this system you could have turn only at your mid-ship lights if you can find the converter and splice into the turn wires upstream of it. In the past 15 years GM has gone back and forth between the two systems, not sure about Dodge, and I think Ford has stayed American style throughout. Big trucks are wired with dedicated/independent circuits and so are their trailers. As a result they have a 9 pin plug.

[larry337]

Originally Posted by PerryB

Big trucks are wired with dedicated/independent circuits and so are their trailers. As a result they have a 9 pin plug.

??? The semi's that I drive have a 7 pin plug. There might be a 9 pin application for special equipment but I haven't seen one.


Sent from my SM-G920V using Tapatalk

[PerryB]

Originally Posted by larry337

??? The semi's that I drive have a 7 pin plug. There might be a 9 pin application for special equipment but I haven't seen one.


Sent from my SM-G920V using Tapatalk

I'll go look at mine when I get over to the shop tomorrow, but I thought it has a 9.

I once had a 5th wheel (RV) that had a dedicated 12v feed for a 3-way fridge. I know that had a 9 pin plug. Maybe thats where I'm getting my wires crossed. -- wow, bad pun.

[larry337]

I dont know much about the circuits of either a camper or a semi trailer but when you think about it a semi has air brakes so that's one less wire needed, so still having 7 would indicate some extra circuits. I know on ours the running lights are on 2 different circuits so if one fails the trailer still has some lights when going down the road.

[1995Suburban]

The air brakes have nothing to do with the brake lights. There is still a wire to activate the brake lights, regardless of braking system.

Sent from my SM-T217S using Tapatalk

[hankaye]

Howdy All;

Every semi I ever drove (18 years, '85 -2003), had a 7-pin plug, some with
round pins and the rest just like the one on your RV. Wiring is the same
as well.

In my first post I forgot to mention that a lot of the older Brake/Turn Tail
lights with 2 filaments (staggered studs so they should only align on way
(some very determined folks can get them in backwards), and the side
marker/turn indicator lights only had/have a single filament (doesn't matter
what their orientation is). I'm thinking that the turn/brake/tail was an 1137
and the single was an 1135. Anyway, I goofed by not expanding my reply
and (mistakenly), thought someone else might fill in the blank, so-to-speak.
Sorry about that.

hankaye

[PerryB]

Originally Posted by 1995Suburban

The air brakes have nothing to do with the brake lights. There is still a wire to activate the brake lights, regardless of braking system.

Sent from my SM-T217S using Tapatalk

What Larry said about one less wire is correct. There is no power supply wire present because the brakes are air actuated. We were referring to the total number of pins required in the plug.

[1995Suburban]

So how do the brake lamps know when to illuminate on the trailer when the brake pedal is applied? Yes the trailer brakes are air actuated, but the lighting circuit is still activated by the brake pedal in the tractor cab.
I am a cdl holder. All our trucks have a 7 pin round umbilical, vs thr rv 7 pin blade umbilical. What the pinout is for each, im not certain yet.

Sent from my SM-T217S using Tapatalk

[1995Suburban]

image off Google showing the pinout of our rv connection vs a tractor trailer.

Sent from my SM-T217S using Tapatalk

[larry337]

Originally Posted by 1995Suburban

The air brakes have nothing to do with the brake lights. There is still a wire to activate the brake lights, regardless of braking system.

Sent from my SM-T217S using Tapatalk

That's not the point. On a camper with electric brakes there is a wire, so a semi would require one less wire. But then I guess the same wire could control both the brakes and the lights. IDK.

Sent from my SM-G920V using Tapatalk

[larry337]

Looking at the diagram fir the camper the brakes are on terminal 2 and the brake lights are on 5 and 6 combined with the turn signals. On the semi the running lights are split as I said between terminals 2 and 6. The brake lights are not on the same wire with the turn signal and have their own wire on terminal 4. What all this means to the OP I have no clue lol.

Sent from my SM-G920V using Tapatalk

[whitescrew77]

Yes trailer usually use the same wire for both the turn signal and the brake light. To get just the turn signals, you need a diode box to only light up the side markers whenever the turn signal is flashing from the tow vehicle. On Amazon I found a taillight converter box for $21. It is the Tow Ready 118158 Taillight Converter with 2 wire systems. It gives you independent left and right turn lights, and also a brake wire light. Just don't use the brake light wire and put the turn signal wires to your new side marker turn signals. Works great.