Multiplex electrical systems evolving rapidly

Jan. 1, 2002
BOB Dannenberg says companies have been toying for years with multiplex electrical systems in medium- and heavy-duty trucks, but not to the degree that

BOB Dannenberg says companies have been toying for years with multiplex electrical systems in medium- and heavy-duty trucks, but not to the degree that International Truck and Engine has with its High Performance Vehicles that were launched almost a year ago in Las Vegas.

In “Truck Multiplex Electrical Systems Are On Their Way,” scheduled for 9:30-10:45 am Thursday, Dannenberg will explain the basics of the architecture and technology and delve into how multiplexing helps automate tasks and eases the relocation or addition of switches, improves the reliability and lifespan of wiring, and allows for advanced diagnostics and programming.

“We'll try to make it clear that this is not like any electrical system there's ever been in any commercial medium- or heavy-duty truck,” Dannenberg says. “The old trucks were pretty much hard-wired point to point. Our wire bundles were getting so large we could hardly close up the instrument panel into the cab. Things are radically different now. We'll try to compare and contrast where we have been, where we started in the late '80s, and how things have evolved.”

Dannenberg says when International installed the multiplex electrical wiring architecture, it wasn't simply to make its trucks easier to sell, but to prove that it was trying to make it easier for bodybuilders to interface with the chassis.

“If a rolloff wrecker or a garbage truck wants to mount those kind of bodies on our chassis, there are typically a half-dozen lights or alarms or other switch inputs the bodybuilder has to first off find a way to mount switches in our cab,” he says. “He'll cut a hole in the floor, cut a hole in the dash. Some guys would take the instrument panels completely down so they could get at a place to mount switches and start cutting holes to mount their switch panels, just start hacking and whacking into our electrical wiring to find good power, good ground, a place to mount their relays. Then they'd take the load wires back out to the cab and string them up their body to their various loads.

“With the new electrical system, we provide factory-installed, pre-programmed switch packs already installed in the truck, and an electrical remote module mounted somewhere on the frame rail. All he has to do is make up his body wiring to terminate it in one of our eight-way connectors and put it in our module on the frame rail, stick some labels on the rocker switches that we've already pre-engineered as a strobe light, spreader, beacon, whatever … and then customize those switches to the loads he has, and he's done.

“There will be more multiplex modules in the future as we start to visit all these bodybuilders so that we can understand how they do their business and see if we can come up with a turnkey solution they can buy from us factory-installed, instead of going to a third party. We're trying to prove to them we can give them a more cost-effective solution.”

About the Author

Rick Weber | Associate Editor

Rick Weber has been an associate editor for Trailer/Body Builders since February 2000. A national award-winning sportswriter, he covered the Miami Dolphins for the Fort Myers News-Press following service with publications in California and Australia. He is a graduate of Penn State University.