Device for checking 7 blade trailer lights WITHOUT vehicle - anyone know of one?

[the old grind]

Yes, that's enough. Pinout is std & no secret so one should only need the 12v battery and a few wires/clamps/probe to test trailer wiring, except maybe braking current. Write down a guide for which pin/color is which and update as you test/confirm. Working in lower light can help vs a spotter out back to confirm what/which light up. You got this.

btw, thanks for a great (specific, relevant) thread title that will guide others to find & benefit with say a Google search.

 

[amhicks21]

all ya need is a 12v battery and 2 wires.

 

[CobyRupert]

^ Yep.

Heck, a 6V lantern battery might work.
….90% of the time there’s a 100% chance you have a bad “ground” (/return path).

 

[Slowpoke Slim]

IPA Heavy Ranger MUTT Trailer Light Tester For Commercial-Type Trailers , Model# 9102 | Northern Tool

The IPA® Heavy Ranger MUTT® Trailer Tester for Commercial-Type Trailers reduces guesswork and saves time by powering each...

www.northerntool.com

That's for commercial trucking trailer plugs.

7 pin round pin plug tester.

Standard plug on most non-semi truck trailers (trailers with brakes anyway) is a 7 pin flat pin.

 

[newbury]

One of MY problems in trying to find parts for making my own test "box" is that about 10 years ago I bought an "extension" cord for the 7 way with a vehicle (male) blade plug and it doesn't have the housing with the little "flip" cover. Has worked great for me, but now I can't find one WITHOUT the housing.
So I'll give up and buy one like this, with the housing.

 

[Xfaxman]

Many years ago I made one using a 12 volt low voltage lighting transformer and some switches to test turn signals and running lights.
Mounted the connector in the box. Trailer lights worked fine on AC.

Edit: This was before LED lights were used on horse trailers.

 

[ROUSTABOUT]

We had a little red wagon from somebody's kid. 12 volt battery and some jumper wires. Kept all the tanker trailers checked at a haz mat chemical trucking yard. They don't get no stricter than that.

 

[newbury]

Do LED trailer lights work fine on 12v AC?

 

[LD1]

Have used two methods.

First is the plastic box with 7-way and some toggles. 4 to be exact

One toggle for left turn, one for right turn, one for running lamps, and one for electric brakes.

That's it. That's the only 4 things you need to test. Most equipment trailers don't have reverse lights. Don't need anything fancy or flashers or anything.

The other method is a battery and alligator clips.

Careful with modern battery chargers....they may not work for this. Alot of newer chargers won't put out any juice unless hooked to a battery.

 

[Slowpoke Slim]

Do LED trailer lights work fine on 12v AC?

I can't say I've tried them on 12v AC.

12v DC, sure.

Like others have said, a 12v battery and some wire and clips is really all you need. You can get fancy about it sure, but the basic battery+2 wires+clips to clip to the battery terminals+a clean connection for the negative terminal (-) to ground on the frame+alternately touching the end of the positive (+) wire to each contact in the round plug.

Really the hardest part is getting a good ground. I've just run a self tapping screw into the trailer frame at the tongue, with a ground lug on it and crimped ground wire to the lug.