Service Bulletin #3
CUSTOM BATTERY BOX
Field Failure: The Power Touch System’s functions
erratically. System may also intermittently shut itself down, turning off all
lights and equipment.
Unit: New truck in service for 1 to 6 months.
Cause: The “Ground” cable
from battery Neg. terminal to the Battery Box, or box bracket, was no longer
provided an adequate electrical ground.
Diagnosis: The custom battery box is located in the center of this
vehicle. The batteries are grounded to the battery box. The battery box is
mounted to the vehicle cross members which are attached to the c-rail frame.
The installation was expedited by the use of self-tapping (shoot) screws into
pre-painted structural members. Shoot
screws do not develop adequate tension to prevent vibration, moisture, and
oxidation from eventually developed inside the assembly until an electrical
connection fails. This practice provides a predictably unreliable electrical
ground return for the vehicle electrical system.
Service: Customer installed a new battery
ground cable to the “C” Rail Frame.
Recommended Corrective Action:
During installation of Custom Battery Boxes a proper electrical ground,
independent of mechanical ground, should be installed. A ground needs to run from the battery Neg.
post to the drivers side c rail through a minimum of a 2awg ground strap. This gage wire will handle 200 amps of
current for the length required. The
cable connectors shall only be crimped with an approved ratcheting crimp tool
specifically designed for the size wire and connector used. And the connection to the frame will be made
with a properly tensioned nut and bolt to clean bare metal or to a similarly
clean welded stud.