Electrical Connectors Explained

Deciding which electrical wiring terminal is right for your application can be a daunting task. Let us help!


We currently offer 3 lines of electrical connectors, all of our electrical terminals with the BAS line code are a high quality alternative, most of which are manufactured right here in the USA. Our NB line offers 3M® products for our customers that want the high quality products and reputation of 3M®. Our EC line has a limited number of economy grade connectors, which are manufactured over seas.


Let Buy Auto Supply be your source for quality automotive repair supplies and electrical connections!


What are the differences between non-insulated, nylon insulated, vinyl insulated, or Heat Shrink Insulated? Which is best?

Below is a list comparing the different types, use the list to help decide the best terminal for your application. If you have additional questions please contact us!


How do I know which one is right for me? Should I just buy the cheapest one?

It is important to choose the right connector for your application, the cheapest option will not always result in the best repair, see our chart below or contact us today!


Why do you only offer a limited number of terminals and connectors when there are so many available? 

We started with a selection of the connectors and terminals most commonly used by shops and installers. We are working to grow our selection and bring you more options. Please contact us if you need a terminal or connector we do not currently have listed. We can source it quickly from our USA manufacturer.


We have access to a full line of high quality connectors from our USA manufacturer, if there is a connector you need that we do not currently stock, contact us today and we can get them quickly!


Types Of Connectors


Non-Insulated Terminals:  

Use non insulated electrical connectors where a permanent solution is needed. When installed properly bare terminals will provide the best long term results. The best wire connector solution for use in engine bays, also available in high temperature steel versions for high voltage applications. 


For best results, use with an adhesive lined heat shrink product. Place the heat shrink around the wire, crimp the connector or terminal to the wire using a crimping tool then solder the wire into the terminal and heat the shrink wrap around your connection for an OE finish with lasting corrosion protection.


Also known as bare, uninsulated, or naked connectors



One of the least expensive options.
Can be installed with solder for an OEM quality repair.
Easy to apply heat shrink for the best protection available.
Crimp area exposed for easy installation and a good connection on the first try.
High Temperature versions offer protection up to 900° F.



No insulation, so they must be covered with heat shrink or another protective coating.
Longer installation times compared to Nylon or Heat Shrink Insulated connectors.
High Temperature options require significantly more force to crimp, often requiring a special tool.




Nylon Insulated Terminals:


Used on 12 volt systems for connecting wires for system accessories inside the vehicle. Not well suited for connections made inside the engine bay or externally on a vehicle were terminals are exposed to the elements.



Easy Installation for quick connections on anything that is not exposed to moisture or other elements, such as ignition interlock systems, stereos, alarms, and other custom 12 volt electronics.
Semi-Transparent case allows you to see if the wires are properly in place, an advantage over traditional vinyl insulation.
More resistant to chemicals and aging compared to vinyl.
More flexible, resistant to cracking and splitting compared to vinyl.
Can be double crimped.
Easy crimp on connector installation.



Wires can be prone to pulling out.
Not a sealed connection, which can lead to corrosion if they are exposed to moisture.
Typically more expensive than vinyl and bare.


Heat Shrink Insulated Terminals:


We currently stock butt connectors with heat shrink insulation, we will be adding more to our inventory soon! If you have bulk needs for other styles please contact us!


These are a great solution for areas were you need the versatility of a quick installation crimp on style connector like a nylon or vinyl connector, but also require a fully insulated connection resistant to the elements. Once you install these connectors simply apply heat to shrink the tubing around the wires.



Quick solution anywhere a fully insulated connection is required.
Easy to install with a crimp on design.
Eliminates the extra step of adding heat shrink to a bare connector.



Significantly more expensive than using a bare connector and heat shrink. 
Can not be soldered, resulting in a weaker connection.
Can be prone to damage on installation leaving a potential for exposed metal.


We stock terminals covering the most common automotive, boat and RV electrical applications including butt connectors, spade connectors, ring connectors, T-Tap displacement connectors, quick connectors and more! 



Have Additional Questions?

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