A Word About Crimping Open Barrel Terminals

By Al Campion


So what is an open barrel terminal and why is necessary to have a special tool?

An open barrel terminal is just about every terminal used on a modern automobile. Packard 56 terminals, Packard Weather Pack and Metri-Pack terminals, AMP MATE-N-LOCK Terminals are all examples of open barrel crimp terminals.

The open barrel crimp is one of the best crimps developed for creating a low resistance connection between the wire and the terminal and must be crimped with the proper tool. It is more difficult to properly roll the tabs into the wire and crimp it with sufficient pressure to keep the wire from pulling out. Wiring harness manufactures use very expensive mechanical presses that produce consistent and repeatable crimps time after time. Professional repair technicians use expensive ratcheting hand crimpers that also produce very nice crimps comparable to the large automated presses. It is also important that the terminal be properly sized to the gauge of the wire. It can be very hard to tell which terminal is for what wire size so I always suggest that you label your storage containers so that you know at a glance what sizes you have in stock. High dollar ratcheting crimpers do the best job but are hardly worth the expenditure if you are only going to make a few connections while rewiring your car. There are some relatively good, inexpensive tools around that will do an ok job of crimping these terminals if you are careful. I found one in a hardware store many years ago for less than 20 bucks that does a very good job (wish I could find a distributor for them). We stock two different models one that crimps 7 different sizes ($ 42.00) and one that crimps 3 sizes ($ 33.00).

So what does the average home auto enthusiast or mechanic do to get a good connection if you don't have the right tool? Simple, get a good soldering iron (a 65-100 watt iron is good for most light automotive uses, 200 watt is better) and a roll of thin rosin core solder (60/40 tin/lead of .025 to .040 inches in diameter). Pre tin the center of the terminal between the forward tabs with a bit of solder and tin the very tip of the stripped wire. Don't get carried away with the solder, just a tiny bit is all that is needed. Place the wire into the terminal and crimp the best you can with what you have for a crimper (don't over do it - just snug will work). Next, with your soldering iron, apply heat to the end of the wire at the crimp you made until the solder flows. If necessary add a tiny bit of solder to the very end of the wire (remember too much solder is NOT a good thing, just a little dab will do ya'). You don't want the solder to wick up into the wire insulation, as this will cause the wire to break at this point due to vibration. Finally crimp the back ears over the wire insulation (after it cools) and insert the terminal into its connector housing.

Wire Size (AWG)      Soldering Iron Size (Heat Capacity) 
    #20 - #16                       65 Watts    
    #14 & #12                      100 Watts    
    #10 & #8                        200 Watts

Hope this helps.



Need any help with your wiring problems just e-mail me. Any and all comments are welcome. If you feel something should be added please let me know. 


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