checking exterior lights

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.

select your connector diagram from here.wiring diagrams
Use a short piece of wire to jumper between the lighting pins and the pin used for battery charge from the TV.
This will test trailer wiring using the trailer battery.
Remember that it does not guarantee lights work from the TV.

Thanks for the info however, a while ago I had seen a gadget that you plug in to the pigtail of the trailer on the front end that would activate the marker lights etc.

I have LED's in these sockets but there are times they have loosed up.

If you don't mind sharing, where did you get your led bulbs.

Plug in the truck when you're ready to leave. Turn on the lights and four way flashers and do a walk around. Check the tires on the way.

Check the tires and lights before every departure!

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.

I've had 1 LED side marker light fail completely (on a 5 year old RV) due to water incursion, and one cabover clearance light has dimmed to the point where it's almost not visible. It's the middle light in a light bar of 3, so I'm not sure what happened to it but I'm not planning on replacing it.

Checking the lights is still important, even with LED's.

Some people plug in a standard two prong flasher unit to flash their trailer lights. It goes between battery terminal and the running light pins

Put a jumper between pin 3 and pin 4 will activate the running lights.

YouTube is always a good thing to check

Light hack

And there is This one

I use a standard Auto Flasher ----- plug it in to end of umbilical cord ---trailer battery then activates all trailer lights and will FLASH just like turn signals