TAMPA, Fla. – Using the proper techniques when making wiring system repairs is essential, but so too is using the right equipment. And that extends to the wire itself.

Panelists at a Technology & Maintenance Council seminar expressed frustration at the amount of general purpose thermoplastic (GPT) wire that’s used in trucking operations, an application for which it’s just not suited.

“Selecting the right wire is important for so many reasons,” said Fred Kelley, engineering director with Prestolite. “It has to be dimensionally right to fit into the connector and seal the system and the other thing is, we have designed the product to live in the environment and handle the fluids, abrasions and all the other things you’d expect. If you’re buying from a local establishment product that does not have those certifications listed, you really don’t know what you have and they typically don’t have the performance you need and you’re going to have problems.”

Greg Jordan of Truck-Lite said he has often walked into a fleet’s parts room to find “reams” of 14-gauge GPT.

“Nobody knows why they bought it,” he said. “They just use it to fix other wires, but it’s very important to educate your purchasing manager, store room people and mechanics on the proper choice of wire.”

To emphasize the importance of using the appropriate wire to ensure a good connection seal, Kelley offered the following experiment:

Noting there is air space between the individual strands within a wire, Kelley said its crucial to keep moisture out. Over time, thermocycling can cause moisture to get sucked up between the strands. To demonstrate, Kelley suggested placing a hot cup of coffee on a napkin and then placing a candy cane-shaped strand of general purpose wire into the cup and up over he edge.

“In a short period of time, that coffee will migrate up through the wire and start dripping on the napkin below,” he said. Anti-wicking conductors in good, quality wire provide additional protection, he added.