Easy way to check operation of your trailer lights

[Blotto Bros]

Years ago I was on a police department and during training I learned a great time saving lesson. Our patrol cars were stored in a garage under the court house and every time my training officer pulled out he would pull into a parking spot and look into the rearview mirror. I am sad to say that it took me a week to realize he was using the plate glass doors of the court house as a mirror to check the operation of his tail/brake light.

I still use this trick today whenever on the road and I want to check my trailer lights...I simply pull into a strip mall and use the store windows as a huge mirror.

[Aaron Coffee]

I do the same, usually leave for work in the dark, so as I am backing out of my space I look in the rearview for the reflection off of the other cars, or if I forget that I usually watch the rearview going down the road for the reflection off of traffic signs, works great to tell that the breaklights are working.

[planovet]

I do the same with my patrol car. The windows at the station are mirrored so I can check my overheads without leaving the car.

[starleen2]

My wife usually puts me out to walk around back to check the lights

[Dale M.]

IF store window or what ever is not available... Just turn on lights, and emergency flashers.... One trip back verifies all...

Dale

[dh]

Thats what I do. I make it part of the walk around check.

IF store window or what ever is not available... Just turn on lights, and emergency flashers.... One trip back verifies all...

Dale

[glenpinpat]

4 way flashers on many vehicles run on a seperate relay then the signals so you may still have a signal out if you only use 4 ways. Also the 4 ways will cause the running lights to dim or fade when they come on so you may not have running lights. I drive for a living and it only 2 years ago I discovered this by accident(another driver told me I had no lights on the back of the truck). I had used the 4 way method up to then and never thought anything of it. I do use the reflection method for checking my lights both front and back.

[Dale M.]

4 way flashers on many vehicles run on a seperate relay then the signals so you may still have a signal out if you only use 4 ways. Also the 4 ways will cause the running lights to dim or fade when they come on so you may not have running lights. I drive for a living and it only 2 years ago I discovered this by accident(another driver told me I had no lights on the back of the truck). I had used the 4 way method up to then and never thought anything of it. I do use the reflection method for checking my lights both front and back.

On most trailers the stop and turn signals and hazard lamps use same wires and bulbs.... You are checking wiring and bulbs.... IF wiring and bulbs are good on trailer, ANY functional problem has to be in tow vehicle....

If hazard lamps cause running/marker lights go dim, you have a wiring (possibly ground) problem.... NOT a functionality problem....

Try increasing size of ground conductor from TV to trailer to prevent dim out....

Dale

[glenpinpat]

you are right on a trailer but op was talking about vehicle(I think) and not trailer.

[Dale M.]

you are right on a trailer but op was talking about vehicle(I think) and not trailer.

It's probably immaterial if it was just TV lights or whole rig.... Its the concept....

If I hook up after dark ... I just look in mirrors and watch the glow.... During daylight I do the walk...

Dale

[doghouse]

wife would walk out and look at the tires, and then the lights as I backed out of the drive way, giving a thumbs up, if all was ok.
I really appreciated it, but finally I told her -Honey, you probably should wear pajamas or night gown, when you wave good by every morning,
since you sleep in "AU natural" its quite a wake up for the neighbors!!!!

she reluctantly agreed, mornings just aren't the same!

[Richard A.]

As someone who has the habit of backing into a parking space (so that I can more safely pull out) ... I use this trick to check the rear lights on my car (I don't back-in when towing) at places (convenience store, etc) that have floor to ceiling glass windows.