Truck Parts and Service | Heavy Duty Trucking, Aftermarket, Service Info
Issue link: http://read.dmtmag.com/i/340589
13 Tech Updates P hillips Industries says voltage drop is one of the easiest testing procedures for diagnosing electrical problems. Completing a voltage drop test is simple and will elimi- nate costly replacement of non-failed parts. To perform a voltage drop test on a sealed harness system, use a multimeter and the following steps, Phillips says. Power up the tractor or trailer circuit you are testing by turn- ing on the ignition and making sure you have power to the components. Take the voltage at the power source for the component. On tractors it will usually be at the batteries, the alternator or power distribution panel. On trailers, unplug the 7-way cord at the trailer and measure the voltage at the plug on the cable of the circuit you are testing, (running lights, clearance, brake, etc.). If the voltage is acceptable, then plug the cable back in. With the power on, test the voltage from the sealed harness beginning at the component that appears to be faulty. If the voltage is good, the component is bad and needs to be re- placed. If the voltage is outside of the range of expected drop, then work your way back at each harness connection and take the voltage to determine which section of the harness the issue is in. If you fi nd corrosion in a connection, you can try to clean the male and female terminals with a wire brush. Once the connectors are clean, place non-conductive grease in the connector, and plug the connection together. Go back to the component and take the voltage to confi rm the voltage drop is resolved. If the corrosion is beyond cleaning or if the problem is in- ternal to the harness, replace the harness or harness module. Do not attempt to cut, splice or repair a harness as it almost always will lead to a future problem. It is always recommend- ed to replace the harness. The cost to cut, splice and repair a section is almost always more expensive than replacing the harness and replacement avoids potential future issues. W W W . T R U C K P A R T S A N D S E R V I C E . C O M J u l y 2 0 1 4 | T R U C K P A R T S & S E R V I C E 2013 NORTH AMERICAN HEAVY-DUTY VEHICLE CHEMICAL AFTERMARKET NEW PRODUCT INNOVATION AWARD Prestone also offers Diesel Exhaust Fluid (DEF) for your Heavy Duty Vehicles. 222-"./+*"+))*! +)6 Email: OrdersPrestoneCommand@Prestone.com With patented anticorrosion formulas, Prestone Command ® offers improved engine protection for any heavy duty engine and is compatible with any heavy duty coolant. Frost & Sullivan has recognized Prestone Command ® as a true innovator, with its advanced technologies that offer increased value and ROI through decreased truck maintenance costs. PRESTONE PRODUCTS CORPORATION, 1900 West Field Court, Lake Forest, IL 60045 ©2014 Prestone Products Corporation *Frost & Sullivan provides market research and analysis to global industry leaders from key industries, including Automotive and Transportation. "Prestone Command ® line of heavy-duty antifreeze offers an innovative solution to fl eet owner-operators looking to improve their ROI for maintenance expenses by providing several advanced formulations to meet a variety of needs." — Frost & Sullivan* Taking Command of Maintenance Costs Requires Prestone Command ® Premium Antifreeze/Coolant ANYWHERE. ANYTIME. ANY ENGINE.™ Text INFO to 205-289-3544 or visit www.tpsdigital.com/info ADDRESSING VOLTAGE DROP