(817) 377-WIRE (9473)
Request a Quote

What are Filler Plugs and Dog Bones? Why Do We Use Them?


Hi! My name is Malich Quijas, Training Manager for InterConnect Wiring where Connections Matter.

Today we are going to be learning about Filler Plugs and why they are an important part of the F-16 Wiring Harnesses.

Previously we had a VLOG where Steve taught you how to crimp a contact and how that was inserted into a connector. However, sometimes all the cavities of a connector will not be used when assembling a wiring harness. In this case the customer often asks to fill the unused cavity with a filler plug or filler contact in the connector.

These ones here are Filler Plugs, they are sometimes called “Dog Bones.” They’re a very inexpensive solution that helps preserve the life of a connector and wiring harness. They do this by plugging any of the unused cavity in a connector. This ensures that no moisture or FOD of any kind can enter the wiring harness through the connector.

Installing the Dog Bone is very similar to installation of a crimped contact. We use this tool that we call an insertion and extraction tool plug the connector. You may have seen these tools before, but as per usual the colored size is meant for insertion while the white side is used for extraction. The different colors represent different size or gauge of wire.

So here we are plugging this connector with some filler plugs. And you can see after plugging them it’s going to be pretty difficult and near impossible for any FOD to find its way into these unused cavities. You have to make sure the filler plugs are seated correctly in order for this to work. This of course if a training connector that will not be put onto any flight worthy harness. Once we put all the filler plugs inside this connector, we now have a fully populated connector.

For demonstration purposes we have an array of filler plugs, also known as dog bones, and an array of insertion/extraction tools. You can see that there is an array of colors which does correlate with the parts color. This red insertion/extraction tool would be used for a 22 gauge connector, a green and white will be used for a smaller gauge like a 26, and this blue and white would be used for a larger size such as an 18 gauge. The filler plugs would also match in a similar format: Black is for a 26 gauge, red is for 22 gauge, blue is for 20 gauge, green is for 18 gauge, yellow is for 16 gauge, and orange is for 12 gauge.

Thank you so much for watching. We are InterConnect Wiring, where Connections Matter. Make sure to visit our website for more VLOGSs, BLOGs, and updates.

Our License

We are the sole licensee of Lockheed Martin for F-16 electrical products. Through this agreement, we have access to Lockheed Martin’s F-16 engineering data, tooling and configuration control information. We also have a Technical Services agreement with Sikorsky for all of their aircraft. This agreement allows us to obtain their engineering data needed to rewire helicopters that Sikorsky manufactures.



Contact Us

    * These fields are required.