This bulletin replaces DSIB 91-1-52 which should be discarded.
Occasionally, proper diagnosis of an electrical problem requires probing electrical circuits for voltage or resistance measurements. Most often this can be accomplished by probing the metal terminal at a connection point. However, there are times when it is easier to probe individual wires with a sharp instrument.
Diagnostic test probes are now available that allow you to probe individual wires without leaving the wire open to the environment. These probe devices are inexpensive and easy to install, and they permanently seal the wire from corrosion.
Figure 2 shows how to install and use the probe device. They are available through GMSPO under the following part numbers:
For 18 (.8mm 2), 20 (.5mm 2), and 22 (.35mm 2) gage wires use P/N 12092782.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.