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Curt Brake Controller Wiring Circuit Tester - 7 Way Plug

Curt Brake Controller Wiring Circuit Tester - 7 Way Plug

Item # C51498
Our Price: $352.48
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Circuit tester helps to quickly identify problems with your vehicle's tow package wiring. Tests brake controller output, brake and battery voltages, and signal circuits. 20' Long cord plugs into 7-way connector for convenient, in-cab testing. 1-636-306-4830 to order CURT accessories and parts part number C51498 or order online at Free expert support on all CURT products. Great prices and Fastest Shipping for Curt Brake Controller Wiring Circuit Tester - 7 Way Plug. Accessories and Parts reviews from real customers.
  • All Info
  • Reviews (5)
  • Q & A (0)
  • Videos (1)
  • Photos
  • Why etrailer?

CURT Accessories and Parts - C51498

  • Trailer Brake Controller
  • Testers
  • CURT

Circuit tester helps to quickly identify problems with your vehicle's tow package wiring. Tests brake controller output, brake and battery voltages, and signal circuits. 20' Long cord plugs into 7-way connector for convenient, in-cab testing.


  • Circuit tester is perfect for installing, setting up, and troubleshooting tow package wiring on your vehicle
    • Helps to quickly identify problems on the vehicle side of your trailer wiring system
  • Uses a volt meter and current meter to measure brake and battery outputs
    • Provides the power output of your brake controller, even without a trailer attached
  • Tests the left turn, right turn, left brake, right brake, tail light, and reverse light circuits
  • Connects to 7-way, RV-style trailer connector on tow vehicle
  • Includes 20' long cable for easy, single-user, in-cab testing
  • Assembled in the USA


  • Application: vehicles being used to tow trailers with 2 or 3 axles
  • Cable length: 20'
  • 1-Year limited warranty

7 Way Plug

The Curt wiring circuit tester plugs into your vehicle's trailer connector to let you know which functions are working properly and which functions are not. It will also show you the power output from your vehicle's 12-volt power wire and from the brake wire. This way you can tell if your brake controller is sending out enough power to activate the brakes on your trailer. The 20' long cord plugs into your tow vehicle's 7-way connector, with plenty of extension for single-user, in-cab testing. No additional power source is needed.

Current and Voltage Gauges

Easily adjust axle load and voltage settings using the switches located on the front of the tester. When testing power outputs, large gauges will display the brake current and brake or battery voltage.

Indicator Lights

Causes of Failure

As you test each of your vehicle's signals, the corresponding indicator light will illuminate when power is detected. Should a wiring issue be present, you can quickly reference the potential causes of tow package wiring failure. This information is conveniently located on the front of the tester.

51498 Curt 7-Way Circuit Test Box

Installation Details C51498 Installation instructions

California residents: click here

Video of Curt Brake Controller Wiring Circuit Tester - 7 Way Plug

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Curt Trailer and Brake Controller Wiring Circuit Tester Review

Male: Today we're going to be taking a look at the Curt Trailer and Brake Controller Wiring Circuit Tester, part number C51498. The circuit tester is perfect for when installing, setting up, or troubleshooting your tow vehicle or trailer wiring system. Now you can test your brake controller and your brakes without the help of anyone else. This is gonna plug into your seven way connector, so lets go ahead and get started. Now it's very simple we're just gonna take the connector and plug it in just as if we we're plugging in our trailers. Now lets head on up to the cab. The cable is 20 foot long it's gonna give us more than enough to get us where we need to be.

The Curt circuit tester gonna help us quickly identify problems in the trailer wiring. It's gonna determine faults in each circuit, such as no load, over load, or short or low battery. So lets go ahead and get started. So we've got our ignition in the accessory mode, so we can insure that we are going to get power to everything need to select which axles we're working with. We're working with two so we got the toggle switch up, lets go ahead and check to make sure we have immediate power to our seven way so we will flip it down; You can see that the voltage reads that we do, that's a good thing. Let's go ahead and run through all the other connections.

Now since we're right here at our break controller let's go ahead and test that first. So it looks like it's reading for the left and right brakes and we can even adjust it again and it's gonna match up perfectly. So when I test the brake controller you can see that the brake current and the brake voltage are gonna line up accordingly. The way it works is, it uses magnets to measure brake control output even without a trailer. Now lets test our vehicles' brakes.

Looks like we're all set there. Lets go on to the turn signals. For our left blinker it looks like it's working, then our right. Let throw on our tail lights, those are working. And then finally our reverse lights, I'd say we're all set. Now for any reason that these don't light up, or doesn't show the correct current or voltage, the seven way could just simply be dirty or could have inaccurate wiring.

And that's going to complete our look at the Curt Trailer and Brake Controller Wiring Circuit Tester, part number C51498.

Customer Satisfaction Score:

Customer Reviews

Curt Brake Controller Wiring Circuit Tester - 7 Way Plug - C51498

Average Customer Rating:  5.0 out of 5 stars   (5 Customer Reviews)

Circuit tester helps to quickly identify problems with your vehicle's tow package wiring. Tests brake controller output, brake and battery voltages, and signal circuits. 20' Long cord plugs into 7-way connector for convenient, in-cab testing.


This is one Awesome tool,Boys. I have 4 trucks,and several trailers.This tool will tell you the whole story with your trailer wiring.The ability to read amperage is very nice,setting up brake controllers.And diagnosing brake problems,is fast and easy.I am very glad I found this tool,and probably will get its partner,for the trailer side.
Thanks etrailer,for this awesome product.


Good afternoon I found your products to be very good quality and I look forward to putting them through the paces considering I work at a training center. Your service reps were very product knowledgeable and answered all of questions and didn't push me toward something I don't want or need. I look forward to working with you guys again in the near future.


Absolutely the best way to function test trailer brake controllers and light systems.
A real time saver! Highly recommend this tool for any serious shop.


This has worked great to confirm truck side plug function and to troubleshoot systems.


Great tester, simulates trailer load. We use it weekly in the shop and find it to be a great timesaver.


See what our Experts say about this CURT Accessories and Parts

  • Does Curt Brake Controller Wiring Circuit Tester # C51498 Show Amperage Draw at Brake Assemblies
    Since the Curt Brake Controller Wiring Circuit Tester # C51498 plugs into the vehicle side 7-way when it is disconnected from the tow vehicle it would not have ability to show any amperage draw on the individual brake assemblies. It can only show you how much amperage your brake controller is capacity of putting out at the connector at the rear of the vehicle.
    view full answer...
  • Can Curt Brake Controller Tester C51521 be Used with Different Brake Controller Brands
    The reason that brake controller tester # C51521 is listed for Curt brake controllers is because of the unique plug that is on it and Curt brake controllers. If you were to cut off the connector on the tester and hardwired a different brand of brake controller to it then it could test other brake controllers other than Curt. Another option is to use # C51498 which plugs into a 7-Way and will test trailer wiring and brake controller wiring.
    view full answer...
  • Brake Controller Not Receiving Power
    In order to determine the problem based upon the information you are receiving from a brake controller tester such as the Curt Trailer and Brake Controller Wiring Circuit Tester part # C51498, I would need to know the make and model of the tester you are using. If you can provide me with this information then I would be glad to help. Although I cannot confirm the error message you are receiving from the brake controller tester, I can however offer my input as to the general cause of the...
    view full answer...
  • Can Curt Trailer/Brake Controller Tester Detect Voltage From 2016 GMC Sierra Brake Controller
    The Curt trailer and brake controller wiring tester # C51498 detects voltage coming from a brake controller so provided that your factory brake controller in the 2016 GMC Sierra is putting out voltage it would detect it. But if all you needed to do was test for voltage you could use a circuit tester at the 7-Way trailer connector, # PTW2993, or a multimeter if you have one.
    view full answer...

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Info for this part was:

Employee Andrew K
Video by:
Andrew K
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Jacob T
Video Edited:
Jacob T
Employee Laura H
Written by:
Laura H
Employee Hayden R
Installed by:
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Employee Wilson B
Updated by:
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Employee Hannah L
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