Self-contained flashing?

BWSwede · May 9, 2015

Has anybody figured out an easy way to have the trailer lights flash when the trailer is parked on the side of the road, but is not connected to the truck, by using the trailer brake battery? I might even be satisfied with just having the lights on and not flashing if flashing adds complexity to the solution.

Maybe just having a trailer plug tapped into the battery so it would be just a matter of unplugging it from the truck and into this plug.

Any thoughts?

TIA,
Blane

orezok · May 9, 2015

Go to RV.NET and ask there. It's common for some stupid reason that some people want their lights on when in a campground. I understand why you might want them on when on the side of the road, but in a campground?

k0ua · May 9, 2015

Blane said:
Has anybody figured out an easy way to have the trailer lights flash when the trailer is parked on the side of the road, but is not connected to the truck, by using the trailer brake battery? I might even be satisfied with just having the lights on and not flashing if flashing adds complexity to the solution.

Maybe just having a trailer plug tapped into the battery so it would be just a matter of unplugging it from the truck and into this plug.

Any thoughts?

TIA,
Blane

To solve this problem, I would start thinking about amp hour capacitys of the trailer battery, current draw of the lights. For instance, are they LED or incandescent? Then think about how long can we power these lamps and is it feasible? If so, then start thinking about the wiring diagram, ease of implementation, whether we need a simple thermal flasher or and electronic one. My first impression, is that this is feasable. How long do you want this to work?

BWSwede · May 9, 2015

Thanks for the replies guys. All my trailer lights are LED. To save me from having to open up that too tight of a box where the trailer battery is located, does anyone know what the amp/hour rating typically is? It is a run of the mill setup by Hopkins I believe.

Blane

k0ua · May 9, 2015

Blane said:
Thanks for the replies guys. All my trailer lights are LED. To save me from having to open up that too tight of a box where the trailer battery is located, does anyone know what the amp/hour rating typically is? It is a run of the mill setup by Hopkins I believe.

Blane

5 amp hours is what I see. So how much current does the LED's draw, and how long did you expect this to work?

PILOON · May 9, 2015

Most flasher units need resistance to operate and LED's have little or no resistance therefore adding a resistor will allow the flasher to work
Seem to recall something in the 10 ohm range did the trick.

On the back of my tractor cab I have a strip of LED's full width that really lights me up for snow blowing.
The usual flasher unit and resistor did the trick.

BWSwede · May 9, 2015

Maybe last two to three hours. If it won't last that long I don't think it is worth doing. I'll have to add up all the watts for all the LED's and see what the total comes to and from there figure out if it is worth it. I don't want to get into another battery just for this.

Thanks for the input.

Blane

wolfpack2 · May 9, 2015

Might be a lot easier and cheaper to just buy a couple of these

Magnetic LED Safety Light (Red) | GEMPLER'S

BWSwede · May 9, 2015

wolfpack2 said:
Might be a lot easier and cheaper to just buy a couple of these

Magnetic LED Safety Light (Red) | GEMPLER'S

That's perfect. Easy, cheap, and can be used on more than just the trailer. We have a winner.

Thank you!
Blane

Sprinklerman · May 9, 2015

I made a jumper with a flasher for my travel trailer . 2 reasons , If I had a problem on the side of the road , and I had to leave the trailer I hook up the jumper and the lights flash using the big battery on the trailer . In the campsite , If someone was looking for my site in the dark , friend , ambulance , beer delivery , I hook up the jumper and I am easy to spot .

Copperhead · May 10, 2015

Per the OP side of the road thing, this is why commercial truck operators have the folding red reflective triangles placed fore and aft of a truck or trailer along side the road, with or without truck hooked up to trailer. That combined with a portable flashing LED light unit or two and you have all you need. Those portable flashing units last around 300 hrs minimum on a set of two D flashlight batteries. All relatively inexpensive, easy to store away, and ready for any contingency. All of my personal and commercial vehicles have a set of folding triangles and a flasher unit. Not just for a trailer situation, but great if one has to change a flat along side the road.

BWSwede · May 10, 2015

The red triangles would be good to have for parking along side of a road. The situation I have coming up is along a neighborhood street. In this case I wonder if a fluorescent cone fore and aft would be better then a triangle.

Thanks again for all the suggestions.

Blane

paulharvey · May 10, 2015

You need to get some of the hi intensity or low intensity flashing lights from traffic barrels, barricades, or signs. There are basically 3 types: low intensity steady burn (most common, used to delineate), low intensity flashing and high intensity flashing. They run for weeks on 2 D batteries. I've seen some now with a very very small solar cell to keep them charged. The high intensity flashing are mounted on advanced warning signs, way above the drivers direct line of sight; the low intensity flashing are used to show a point hazard.

aczlan · May 10, 2015

Do you want to flash the turn/brake lights, or the running lights?

To make the turn signals flash, you would need a TPST switch (3 pole, single throw) switch (like this:5 Pcs ON-ON 3-Terminals Double Pole Dual Throw Toggle Switch 6A 125VAC - Electrical Outlet Switches - Amazon.com) and a electronic flasher relay (such as: Amazon.com: 3-Pin CF-13 Electronic Flasher Relay Fix For LED Turn Signal Light Bulbs: Automotive )
Pin 1 input on the switch hooks to battery positive terminal
Pin 1 output hooks to the B+ terminal on the flasher relay
Pins 2 and 3 input in the switch hook to the L terminal on the relay
Pins 2 and 3 output hook to the left and right turn/brake wires
The E- terminal on the relay hooks to ground

To make the running lights flash, you would need a DPST switch (2 pole, single throw) switch (like this: Amazon.com: Gardner Bender GSW-14 Heavy Duty Toggle Switch, 20A 125VAC, Double Pole Single Throw, ON-OFF, Screw Terminal: Home Improvement) and a electronic flasher relay (such as: Amazon.com: 3-Pin CF-13 Electronic Flasher Relay Fix For LED Turn Signal Light Bulbs: Automotive )
Pin 1 input on the switch hooks to battery positive terminal
Pin 1 output hooks to the B+ terminal on the flasher relay
Pin 2 input on the switch hooks to the L terminal on the relay
Pin 2 output hooks to the running light wires
The E- terminal on the relay hooks to ground

Aaron Z

BWSwede · May 11, 2015

Thanks Aaron. I am saving your post in case I change my mind about using the simple magnetic mount unit that is shown above. You have explained well enough that even somebody like me could correctly connect the wires.

Blane

jaotguy · May 11, 2015

look at red LED bicycle flashing lights ... run on 2 aa's for hours and cost a buck or two at the dollar store ... some double sided tape or magnets glued to the back .... solid light / long flash / fast flash / OFF ....

aczlan · May 11, 2015

jaotguy said:
look at red LED bicycle flashing lights ... run on 2 aa's for hours and cost a buck or two at the dollar store ... some double sided tape or magnets glued to the back .... solid light / long flash / fast flash / OFF ....

I have used those (on bikes) and the big ones from Tractor Supply will be much more visible (while being less annoying to others at the same time).
A cheaper source for the big flasher: Amazon.com: Blazer C6350 LED Emergency Magnetic Light- 1 each: Automotive
Another option (LED "Pucks"): Amazon.com: Wagan EL2639-3 FRED Flashing Roadside Emergency Disc LED Flare, (Pack of 3): Automotive

Aaron Z

ModMech · May 16, 2015

Blane,

At the most simple level, all you need is one two prong flasher, an alligator clip and some wire. The install looks like this:

Battery(alligator clip)------->Flasher-------->Stop light circuit

When you want the stop lights to flash, simply connect the alligator clip to the B+ terminal of the battery, it will power the flasher and the flasher will cycle the brake lights. The only "gotcha" is to make sure the alligator clip doesn't contact metal (ground) during normal operation, it will be "hot" with the brake lights on.