Checking Tailights

[MadMax]

For years I have camped by myself in my fifth wheel and in preparation for departure my last check is for the tail lights. I’ve always turned on lights & 4-way flashers and observed all work at rear of trailer. I suppose I could also check each signal but I assume, if the 4-ways are flashing then the signals should work and the brakes would also work. Is this correct thinking?

[RollaMo]

It would depend on your trailer tail lights.

Some might have dual filament bulbs (one for signals and one for brake lights).
Others might actually have two separate bulbs.

[chuckster57]

I have one of these in my tool box.

https://images.search.yahoo.com/imag...ne&fr2=piv-web

[flybouy]

Originally Posted by MadMax

For years I have camped by myself in my fifth wheel and in preparation for departure my last check is for the tail lights. I’ve always turned on lights & 4-way flashers and observed all work at rear of trailer. I suppose I could also check each signal but I assume, if the 4-ways are flashing then the signals should work and the brakes would also work. Is this correct thinking?

emotional. It would help if created a signature ( now a forum requirement) with the info on your trailer and truck. 99% of the trailer lights work as you describe with dual filimant lamps.

[{tpc}]

I’ve used a block of wood to wedge between the brake pedal and the seat before so I could go check the brake lights on my own.

[bsmith0404]

In theory it works that way. I used to do the same thing when I was transporting. One day a trucker called me on the CB and told me the turn signals were backwards. I stopped and checked them, sure enough the trailer was wired backwards. Had to do some rewiring in a Walmart parking lot now I always check the turn signals individually. I know mine is wired correctly, but wiring issues, bad grounds/shorts, can cause some strange things.

[MadMax]

Thanks to all.

[NH_Bulldog]

To the OP, keep in mind that your method only checks whether the bulbs work (which is most of the battle). However, it doesn’t tell you if your brake lights come on when you step on the brake, or whether your turn signals are coordinated (left light flashes left and right light flashes right).

[flybouy]

This is real simple folks, here's the 7 way color code:

Green: Tail/running lights
Yellow: Reverse Lights
Brown: Right turn/brake light
White: Ground wire
Blue: Brake controller output
Black: Battery hot lead
Red: Left turn/brake light

If you're rig has a 7 way plug then the brake light AND the turn signal are transmitted over a single wire for each side. Therefore, if you turn on the running lights and the 4 way flashers you are testing all of the lighting circuits from the truck to the trailer.

If you want to verify that left and right turn signals are wired correctly then you only need to go that one time unless someone works on the 7 way wiring.

[dutchmensport]

Running lights and turn signals can easily be checked one by one by simply stepping behind the camper (exactly like checking the 4-way flashing lights). It's the brake lights that you need assistance with. The block of wood against the brake pedal is a really good idea. You could even use an umbrella, a broom stick, a walking stick, or even a walking cane. Another option is to set up a small mirror behind the camper on a tree stump or something. But the angle has to be just right. But it is a suggestion how you can do it alone.

[Weldon]

I have this tester that i picked up at my local northern tool store

https://www.northerntool.com/shop/tools/product_200466892_200466892

[ssthrd]

I whittled a small tree branch about an inch thick with a crotch on one end
to fit the steering wheel and long enough so that when in place on the brake pedal, it is depressed maybe an inch to activate the brake lights.

Looks cool and is crude but effective.