🔑 Convenient Keychain Wire Tester: Hopkins 48655 for 4 Wire Flat Review

The little fool does exactly what it is supposed to do, and it comes in the simplest packaging. Tests any 4-pin wiring for efficiency and continuity.

I tried to remove the wires on the trailer and asked this little guy to make sure it wasn't my Jeep. Worked great and is a perfect inexpensive tool. I'm sure this will come in handy quite often.

Planned to tow a small portion of our household and needed to check the tow bars. It's plug and play. Just make sure it's fully inserted or you'll think your setup isn't working.

I think they are essential if you have four flat wires. Quick and easy troubleshooting BEFORE hitching your trailer means less work. They are easy to connect and check the wiring. Highly recommended for those working with four apartments.

I used this to determine if my trailer or truck had a wiring problem. I connected the device to the truck and found this to be an issue covered by my truck's warranty. Saved me from having to fix a trailer wiring issue that wasn't there.

What can I say? This is a tester. Plug it in, the indicators will light up when the pen has power. Makes testing easier. I installed new wiring and headlights on my trailer last fall, but before using it for the first time I bought a 2014 Silverado. A bulb stopped working the first time it was used. I needed to know if it was a truck or trailer problem. I bought this and confirmed it was a trailer issue (bad bottom, easy to fix). Now I keep it in my truck's tool box.

This simple block works great. These little testers may seem totally unnecessary, but if you're having trouble with trailer lighting, they can be invaluable. Apparently, lighting problems can be due to the tractor or trailer. This way you can diagnose what the problem is. Additionally, if your trailer is stored off-site, you can check the trailer-to-tractor connection before you attend to the trailer.