Your choice of wire harness tape is essential to modern automotive assembly. The vehicle wire harness connects everything from dash-mounted displays and speaker systems to turn signals and power steering. With the growing prevalence of screens, charging ports, cameras, and computer-powered elements in the vehicle, secure wiring has become an even greater priority.
Damage to the electrical system can be catastrophic, leading to critical system failures, fires, and more. Tapes that bundle the wires must resist extreme heat or cold, exposure to chemicals, and potentially even abrasions from rocks or road debris (such as in the engine bay). A great vehicle wire harness tape will do all of these while remaining reliably adhered to any space, whether cramped or open to the elements. Here are a few traits to look for:
A Tight Wrap
PVC has been the most common wire harness tape in the industry for a long time (and still is among Japanese automakers). As a flexible plastic, PVC enables tight, form-fitting wrap-around wire bundles that must navigate increasingly tight spaces in today’s device-laden but (lightweighted) vehicles.
Wire harness tapes are rated A through F on how well they resist abrasions (with A representing virtually no resistance, and F extremely high). According to international standard ISO 6722, the scrape abrasion test involves rubbing an abrading tool back and forth across the tape under specified pressure and conditions. Class A tapes survive fewer than a hundred strokes, whereas Class F will withstand over 15,000 before failure.
Cloth polyester tape has risen to greater prominence over the last decade for it’s impressive resistance to heat and abrasions. It’s also highly flexible and easy to tear by hand for manual application (still the standard for wire harness tape). When polyester is nonwoven (fleece or PET felt), it’s also effective for sound attenuation.
The toughness of modern textiles has pulled manufacturers slowly away from the old standby of PVC tapes.
Insulation From Heat and Electricity
This is another area where PVC shines, as it’s a powerful electrical insulator. However, the engine compartment’s high temperatures may encourage automakers to consider options such as polyester, foils, fleeces, and vinyl. Glass cloth tapes are notable for incredibly high heat resistance compared to other textile wire harness tapes.
The tape backing isn’t the only consideration for heat resistance or insulation, though—the adhesive layer must survive temperature fluctuations without peeling and help insulate the wire bundles to which it is adhered.
Resistance to Chemicals and Contaminants
Woven tapes can function well where oils and contaminants are expected, especially if laminated or treated, but smooth polymers and foils will provide the most secure seal. Many modern polymers like polyester and PVC will withstand corrosive substances to protect your vehicle wire harness from damage.
If a cloth tape is necessary or preferred, the backing can be coated to make it flame-retardant, waterproof, or chemical-repellant (as required).
Your choice of vehicle wire harness tape will likely vary throughout the vehicle, and it should. The backing or adhesive layers you select will depend on the location and what threats you anticipate the wires may face in that area. Consult with a supplier of automotive films and tapes for a more nuanced understanding of your options as you search for the ideal wire harness tape.
Cover image sourced from Assembly Magazine.