Component Testing

WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.
The High Voltage Disabling procedure will perform the following tasks:

Identify how to disable high voltage.
Identify how to test for the presence of high voltage.
Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:

Safety glasses with appropriate side shields when within 50 feet of the vehicle, either indoors or outdoors.
Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors.
- Visually and functionally inspect the gloves before use.
- Wear the Insulation gloves at all times when working with the high voltage battery assembly, whether the system is energized or not.

Failure to follow the procedures exactly as written may result in serious injury or death.

Fan Relay Test

Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling .
Ignition OFF, disconnect the drive motor generator battery vent fan relay.
Test for 85-110 Ω between terminals 1 and 2.
- If not within the specified range, replace the relay.
Test for infinite resistance between the following terminals:
- 1 and 3
- 1 and 4
- 2 and 3
- 2 and 4
- 3 and 4
- If not the specified value, replace the relay.
Install a 5 A fused jumper wire between relay terminal 2 and 12 V. Install a jumper wire between relay terminal 1 and ground. Test for less than 2 Ω between terminals 3 and 4.
- If greater than the specified range, replace the relay.