How to Properly Crimp Yazaki YESC 1.5 Terminals: Step-by-Step Guide with Quality Standards
The compact size, high conductivity, and excellent mechanical retention make Yazaki YESC 1.5 terminals suitable for automotive wiring harnesses, industrial electronics, and electrical control systems. Proper crimping ensures long-term electrical performance, vibration resistance, and connector reliability. Improper crimping can cause voltage drop, electrical failure, overheating, and premature harness failure. This guide walks you through the correct way to crimp Yazaki YESC 1.5 terminals step by step, along with essential quality guidelines, inspection techniques, and best practices.
Understanding Yazaki YESC 1.5 Terminals
Yazaki YESC 1.5 Terminals are high-performance automotive electrical connectors. They are marked as "1.5", which denotes a contact blade/tab width of 1.5mm x 0.8mm. Most major automotive companies use them for wire-to-wire, wire-to-PCB, and wire-to-device connections.
Key Features
- Industry Compliance: They conform to very tight USCAR and ISO automotive criteria for durability and reliability.
- Versatility: They come in two types, sealed (weatherproof) or unsealed.
- Kaizen Update: The new YESC "Kaizen" series is fully compatible with the old model of the YES series and is more powerful.
- Wire Gauges: They are usually designed to fit common automotive gauge sizes from 22 AWG to 16 AWG.
Common Applications
- Automotive wire harnesses
- ECU systems
- Sensor circuits
- Industrial electrical assemblies
- Low-voltage control systems
There are male and female terminals, and features include:
- Conductor grips
- Insulation grips
- Lock-up features
- Orientation stabilizers
- Terminal protection structures
The temperature range of the unsealed YESC 1.5 is about 40°C to 100°C, with a maximum temperature rating of 120°C.
Why Proper Crimping is Essential
Crimping creates an electrical and mechanical bond between the wire conductor and the terminal. If crimping is not correct, it could lead to:
- High electrical resistance
- Weak pull-out strength
- Wire strand damage
- Terminal deformation
- Unstable electrical signals
Fitting Crimps will help to keep:
- Low voltage drop
- Reliable current flow
- Strong vibration resistance
- Long lifetime of the connector
Tools Required for Crimping
Set up crimping tools before the crimping operation:
- Precision wire stripper
- Crimping tool, compatible with YESC 1.5
- Loose terminal or terminal reel
- Stand-mounted micrometer
- Inspection magnifier
- Pull test equipment
Use the correct crimping die to ensure compliance with the specified crimp height and width.
Crimping Yazaki YESC 1.5 Terminals Step-by-Step Guide
Step 1: Check the Terminal and Wire
Before crimping:
- Check the proper terminal part number
- Look for rust, damage, burrs, or dirt.
- Check the size of the wire against the terminal specification.
Step 2: Properly strip the wire
Strip length is critical for proper conductor capture. Use a quality wire stripper, such as the IWS-049 Multi-functional Wire Stripper.
Recommended strip lengths:
- 4.5–5.0 mm for medium-sized terminals
- 4.5–5.0 mm for larger wire sizes
Avoid:
- Cutting wire strands
- Diagonal stripping
- Damaging insulation
Damaged conductors will reduce conductivity and decrease terminal holding.
Step 3: Position the Terminal into the Crimping Tool
Crimp the terminal into the proper crimping die and make sure:
- The conductor grip is in line with the bare wire.
- The insulation grip fits on the insulation jacket.
- The terminal is lodged in the tooling and is at the midpoint of the tooling.
Asymmetrical crimps and terminal deformations are prevented with proper positioning.
Step 4: Insert the Wire
When pushing the stripped wire into the conductor barrel, make sure it is completely inserted until:
- The conductor is cut to the correct length of the wire brushes.
- The inside of the insulation grip is lined with insulation.
The optimal wire brush size is between 0.1 and 1.0 mm.
Step 5: Crimp
Squeeze the crimp tool firmly but gently, with steady pressure.
Here are the characteristics of a good crimp:
- Make sure that conductor strands are fully captured
- Maintain crimp symmetry
- Do not overflash or overburr
- Prevent insulation damage
Step 6: Check the Crimp Quality
After crimping, thoroughly inspect the terminal.
Check for:
- Proper bell-mouth formation
- Correct crimp height
- Smooth insulation grip
- No strand cut-off
- No deformation
- Proper insulation capture
No more than the insulation should be visible in the insulation grip.
Reject Terminals Showing:
- Frayed conductors
- Open seams
- Blade deformation
- Excessive twist
- Cracked insulation
Measuring Crimp Quality
Use a stand-mounted micrometer for measurement of:
- Conductor crimp height
- Conductor crimp width
- Insulation crimp height
- Insulation crimp width
For accuracy, measure at the center of the crimp area. Standardized measurements guarantee production quality and electrical dependability.
Best Practices for Terminal Handling
To avoid terminal damage after crimping:
- Don't overbundle wires
- Ensure the terminals are shielded from contamination and dust
- Avoid transporting without wire hanging stands
- Do not bend or repair the terminals
Proper handling helps prevent probing or mechanical damage to female terminals.
Final Thought
Electrical and wire-harness reliability and stability depend on proper crimping of Yazaki YESC 1.5 terminals. Correct strip length, precision crimping tools, and proper quality assurance can significantly improve terminal performance and reduce connection failures. Check out www.iwiss.com for professional-level terminal crimping tools and wire harness equipment, as well as electrical connections, and learn about some high-performance tools for precision terminal crimping.
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