Arrives before Christmas 
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This circuit tester plugs into the 7-way connector on your truck. LED lights indicate which functions (brake, turn, tail, stop, reverse and 12V) are properly working.
Features:
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hey everybody, Ryan here at etrailer. Today we're gonna be checking out the Pollak seven-way circuit tester. What this tool's gonna do is allow you to check the functions of your vehicle's seven-way. So this is a bladed style, so extremely common. You see these on RVs and pickup trucks and SUVs like what we have here today. And it's gonna check all of those lighting functions.
So we're gonna have left turn, TM for taillights, RT for right turn. This one down here will be our 12 volt auxiliary power. BK will check our brake controller output and BU will be back up or reverse lights. And then of course whenever you hit the brakes both of the turn signal lights should illuminate allowing or letting us know our brake signals work. Why don't we get right into it though and check our vehicle's trailer functions.
Make sure the seven way's working. So this will just plug right into your seven way and if the lights illuminate, we know that circuit is working. So right away our 12 volt power illuminated. So we know that's good, but we'll go ahead, get inside the vehicle here and run through the rest of our functions. We'll go ahead and turn on our taillights.
I'll go ahead and turn 'em off and now we'll try our left turn signal, our right turn signal, we'll hit our brakes and if you had a brake controller you would apply power to it to test that function. In our case, our vehicle doesn't have one so we don't have to worry about it but it'll work the same as all the other signals if you do. And then I'll have to start up the truck here, (engine ignites) put it in reverse and test out that signal. A very simple tool and is something good to have especially if you pull a lot of trailers or tow often. And this is just gonna help you isolate a problem.
If you do happen to have one, which it seems like it never fails, you go to hook up to a trailer it's been sitting for a while, seems like you end up running into issues with the light. So instead of wondering if it's your vehicle side or the trailer side, this will help you determine that. So let's just say for example you hook up to your trailer, everything's working other than say, the left turn and brake light signal. What you could do at that point is take your tester, plug it in. If it's working on your vehicle side you need to focus your efforts on the trailer 'cause that's likely where the issue is gonna lie. But let's say you plug this in and it's not working on your vehicles side, that's gonna let you know that something's going on with the truck, right Probably a popped fuse or something along those lines. So you can get that sorted first, hook up to your trailer, test it out, if it's all working like it should, great. If not, chances could be you might have an issue on the truck and the trailer. So it's just one of those things that kind of gets you going in the right direction and makes it a little bit easier to figure out any type of lighting issues that you might run into. Just to do a quick comparison here is a Curt seven-way tester and I really don't have a preference so to speak. it's a pretty simple tool. Either one will work just fine. One thing I did kind of notice with the Curt is that it's a little bit longer and so if I go to plug this into the seven-way, most seven-ways are very similar to this, it comes out a little bit further. So it's a little bit easier to see the lights. Plug this one in, just give you a visual. The Pollak one, not a game changer. But something I did notice, and I will say, with both of these, I've experienced in the past some of these more late model trucks that have factory built-in brake controllers, sometimes a truck is almost too smart and it doesn't recognize these as being a trailer, so to speak. So sometimes if you go to test that function, and that's not the case with every late model truck, just some of 'em that I've ran into. When you go to test that function, sometimes it doesn't really wanna work even though the brake controller is working. Just because the truck's, like I said, almost too smart and realizes this isn't a trailer. But just wanted to mention that in case you run into that issue. But other than that, at the end of the day this is a good tool to have that you can throw in your glove box and could potentially save you some headache whenever you go to hook up to your trailer next time.
Average Customer Rating: 4.7 out of 5 stars (142 Customer Reviews)
This circuit tester plugs into the 7-way connector on your truck. LED lights indicate which functions (brake, turn, tail, stop, reverse and 12V) are properly working.I bought the 7-way LED circuit tester. I bought a used Class A motor home and have had problems with the 7-way plug on the motor home This will help me resolve the last issue. A few weeks ago I had also purchased the 4-way flat LED tester and now have both in my tool box. Thanks
Not much to say about a trailer plug tester other than it works just fine
and is as advertised. Shipping was prompt and I was able to solve my neighbors
wiring problem quickly without a hassle.
If I ever need any trailer related parts or ?? You people will be the first that I will
contact.
Thanks
Roy
10/12/2020
It still works great
It’s a good tool to have to make sure your vehicle’s trailering lighting system is correct before hooking up to the trailer and hitting the road.
Exactly what I needed for a repair!
There have been several times this tool has helped isolate problems with trailer wiring by insuong tow connector AOK. 5th wheel, horse trailer, flatbed, and touhauler all had either a bad connector, a bad wire, corrosion issue, difficult to isolate but easy to repair. Saved a lot of time.
great size and easy to use
The tester plugs in easily and works fine. It's hard to remember what the lights mean. It would be helpful to include a small heavy paper or plastic card that could be carried with the tester that identifies the lights.
works well. worth the price. you have to make sure you get the correct one. those 7 pins can be wired differently. email them and tell them what vehicle you have. some trailer hitches have the groove on top some on the bottom. if yours is on the bottom you will have to lay on the ground to read it, because the lights will be pointing at the ground. the lights are on the groove side.
Super helpful to have one of these testers. I suspected my trailer battery was not getting charged by the tow vehicle, and this tester confirmed the problem was my 12 volt wire is not active. Saved me time as now I know where to go next for resolution. Also easily can confirm my truck's trailer plug works without having to hitch up. Totally worth it in time saved.
Arrived promptly and it worked as expected when I tested it on my tow vehicle. A previous reviewer stated that he wished there was a card that listed what each light tested. It is marked on the plug around the test lights, but the printing is the same color as the plug. That is the only reason that I gave this product 4 stars. I used a paint stick to highlight the markings so that I can read them easily without my glasses.
Good and useful product. Only problem is that if the Pollak keyway on your vehicle is on the bottom side you can't easily see the LED lights! This would be a more useful product if the lights were visible from both sides. Suggest a design change to do that would be appropriate.
I had been looking for a tester like this locally but could not find one. I ordered it and it arrived in short order, it works great and is a great addition to my tool bag!
Blue M.
6/16/2017
Wonderful! Perfect to keep in my door pocket, just to be sure!!
I use it after installing trailer wiring on my trucks. Works great!
Ryan
3/13/2018
It still works fine. No complaints.
This tester makes quick work out of making sure that a trailer plug is wired correctly, I typically use it to make sure that when someone uses one of my trailers that their plug is wired correctly.
This tool reduces effort in hooking up the towed vehicle/trailer to check out trailer wiring. Simple, effective.
Worked well. After testing, my new RV is headed back to the dealer to fix a wiring problem with the trailer light jack.
I love this tester. It showed me right away which circuit on my truck was out. I wish I had kept track of how many people I have helped with this tester. It is a must buy to keep in your tow vehicle.
Just what I needed.... I have 4 trucks and 6 trailers, and when a light isn't working, I have to figure out where the issue is originating.... with the 7-way circuit tester, I now know the trucks are good to go..... thanks etrailer!
It works great. I have used it on several vehicles.
Only problem is using it on GM vehicles the light display is on the bottom side when you plug it in which makes it hard to read.
This is so easy to use. I keep it in the package for the easy to read light definition on the back. I love that the product is shaped like a handle for easy unplugging.
Has instructions on back of package showing positions of all wiring locations
It works, but one of my vehicles is too smart and it does not output a signal unless it senses a bigger load then these LEDs.
Lights r downs on an f250 plugged in to truck
Nice quality device that helps solve problems and gives peace of mind.
never worked from day 1
Jenny N.
10/19/2022
You mentioned that the tester did not work for you and I have a few questions that I wanted to ask. What is the year, make, and model of your truck? Do you still have the tester? Did you try it on other trucks with seven way connectors?
Douglas
10/19/2022
the vehicle is a 2016 silverado c3500 . I do not have any other vehicles to test it on. When hooking up to my other trailer no brakes all seemed ok. The tester showed no lights whatsoever. I do not possess the tester still.
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Gary S.
6/11/2020
Great to have in my tool box. I loaned it to a guy in the camp site next to us.It helped him to locate his problem in minutes. GREAT!