checking exterior lights

The clearance lights are just one set to check. You need to check turn signals and most important your brake lights.

I do as Boon Docker says.
Just put a 5 amp blade fuse at the top between pin 3 & 4 of the pigtail. It will light up all the clearance lights, top & side along with the tail lights..

Boon Docker wrote:
Easy way to not mess up (shorting ground to 12v) is to use an RV blade type fuse as a jumper between pin 3 and 4.

This ^^ easiest way to accomplish what OP wants to do.

The flasher OB mentioned works too, but a bit annoying when attention getters do it in the CG.

Jerry

I could not be bothered to waste my time making a tester box to do a simple and easy one time test of my running lights.
For people that like to make gadgets, go for it. :B

Fuses are always a good idea, but I suspect pretty much no one that professes to randomly stick wires in their trailer connector ever uses a fuse.

Seems like way to many cheap RVrs on this forum.

It also should noted that I have as of yet over the years have never had any RV plug that has "numbers" written on the outside of the connector. Have only seen one that had numbers on the terminals on the inside.

Means that you must constantly look at a pinout chart or diagram to find the pin location, then look and the plug, find the locating pin and pick the correct place to jumper.

I have been doing electronics building and repair and even electrical work things nearly 40 yrs and yet find it very easy to find the wrong connection on those nice round plugs.

That is why I suggested the idea to build your own simple test box, very quick plug in and flip a couple of switches. Sure beats looking at a diagram and the plug and then diagram and then plug..

Heck, to simplify things for myself, I bought a RV socket, brought the wires out, labeled each wire as to function. Fused the battery charge line just in case. Basically making a "break out" box connection.

I used that setup to test last used trailer I bought. Since the trailer didn't have a battery (trailer sat in a campground for 15 yrs when I bought it), I made a 20' jumper with alligator clips and a fuse block and connected that to my vehicle battery.. Needed to safely test without blowing up truck fuses..

Much better more professional ways to do this without randomly sticking wires in a socket.

Easy way to not mess up (shorting ground to 12v) is to use an RV blade type fuse as a jumper between pin 3 and 4.

enblethen wrote:
Flasher is not normally used for testing the lights. People use it to show off their rig or to locate it.
To test you must use a jumper and move it between different pins in the connector.

Understood.

However, sticking a jumper randomly into the 7pin connector any old way you can easily short the battery pos connection to the battery ground connection located on the same 7 pin plug. While it can be done it is much less ideal and a bit more tedious, not to mention highly confusing on which terminal you are about to wire.

Much better to buy a 7 pin socket and wire up with appropriate switches and a fuse on the battery charge line..

Like I mentioned, not all that expensive to wire your own tester box, makes for very quick testing, just plug in and play with switches. No need to check, recheck diagrams and hope you just didn't accidentally pin the ground to battery positive. I think you would be really hard pressed to spend more than $40 in materials to make a real nice testing box.

$7 for the 7 pin socket
$2 for fuse and holder
$3 for each toggle switch



$20 for a big enough plastic electrical box..



That one is 10"x6"x4"

HERE

$38 plus tax all in..

Flasher is not normally used for testing the lights. People use it to show off their rig or to locate it.
To test you must use a jumper and move it between different pins in the connector.

dtappy3353 wrote:
Thanks Old-Biscuit....that's what I was looking for.

Thank you to all who responded.

Old-Biscuit mentioned a turn signal flasher, for testing, you don't need the lights flashing. You really just need them to light up when commanded.

While there is a manufacturer that makes a commercial ready to use tester, it is pretty expensive at $170..



Found HERE

You can easily "build" that same box pretty cheap..

Just need 7 pin socket..



and a few switches and a fuse and a electrical box large enough to fit the socket.

Use the diagram Boon Docker posted.

You can use the battery power from the trailer connector to power the lights, add a small fuse from the battery pin to the switches.

Basically you will need a switch for running lights, a switch for left and right turn and if you have it a switch for backup lights.

All parts could be had for less than $40.

But the issue I see is there is no way to test the brakes effectiveness..

Personally, I just back my vehicle up to the trailer and use the vehicle to test them. No need to hitch up trailer to test.

JimK-NY wrote:
The exterior lights on the trailer operate off of the truck, not the trailer batteries. You need to plug in the truck to verify correct operation.

Do you have issues with burned out bulbs? What are you trying to check before a trip? Most RVs use LEDs and have for a great many years. A burned out LED bulb is rare. I have never had one fail even after years and years of use.

LEDs do in fact "burn out", I have just finished replacing all of my LED markers. After only 5 yrs of only being used two weeks each yr, one by one a LED marker light started to fail is some fashion. The ones I have had 6 LEDs each LED must have been in separate series strings as they tended to fail on half of the fixture and then would eventually fail completely. Have had to replace 3 Bargman tail lights also..

That was just on my TT, my 18ft flatbed trailer, in ten years of owning it from new one atil light and one marker gone, blank, no light, dead.. That trailer gets even less use than the TT..

My TT I was lucky that the lens were not sealed and I was able to relamp them with industrial outdoor sign LED modules that I added a resistor in series to reduce the brightness and increase the life of the LEDs.. Looks like these..



Yes, I did use Red and Yellow modules, they look clear until lit.

So, don't believe in the notion that LEDs will outlast your RV..