Understanding Wire Types
There are many types of electrical wire. Understanding which type is best for your application can be confusing. It is important to make the proper selection. Using the wrong type of wire can lead to failures and fires.
For this article, we will focus on the wire typically used in automotive, boat, RV, and motorcycle applications. Never use wire intended for household use in vehicles, it is not designed to handle the heat, vibration, and chemical exposure.
1.“GPT” or “Primary” Wire
This is the most common wire you find at auto stores. As its name implies, it is a good general purpose automotive wire. It features a multi stranded core and flexible insulation making it ideal for pulling through tight spaces. It is usually rated to 80ºC (176ºF). Although some is also rated to 105ºC (221ºF). It is resistant to oil, chemicals and acids.
2.“1015” “Hook-Up” or “Motor” Wire
The biggest difference between GPT and Motor wire is that motor wire features finer strands of wire. This allows it to handle higher voltages.
Motor wire is rated at 600 Volts with a temperature rating of 105ºC (221ºF). It is resistant to grease, oil, acids, water, solvents, fungus.
Although most commonly used as internal wiring in appliances and HVAC equipment, motor wire is finding increasing use in automotive applications.
3. SXL Wire
SXL Wire features a cross linked polyethylene jacket that can withstand higher heat, abrasion, and aging than GPT wire. It is often the preferred choice in higher stress applications like race or industrial use vehicles. If you are looking for extra durability, this is a good choice.
GXL and TXL wire feature the same type of insulation but thinner walls to make it easier to pull through tight spaces.
Speaker wire is a paired stranded wire intended for audio applications. As the name implies it is meant to carry the 'sound' from a stereo receiver to the speakers. It is intended for low voltage use and should never be used to carry load. Speakers can run in 'reverse' (out of phase) but they will sound terrible - so it is important that the + and - terminals be connected correctly.
5. Battery Cable
Battery cable is typically used to connect the battery to the car’s electrical system (typically at the starter) and ground. It is larger gauge, heavier wire. Battery cables are most susceptible to corrosion, and can often be corroded inside the cable where it can’t be seen. If you are having starting issues, check your battery cables carefully.