Component Testing

WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

PTO Relay (If supported by the PTO upfitter wiring)

Ignition OFF, disconnect the PTO relay.
Test for approximately 50-200 ohms of resistance between terminals H and J on the upfitter wiring side of the upfitter PTO connector.
- If the resistance is not within the specified range, replace the relay.
Test for infinite resistance between the following terminals:
- F and J
- F and H
- F and K
- K and J
- If less than infinite resistance, replace the PTO relay.
Install a 15-amp fused jumper wire between relay terminal J and 12 volts. Install a jumper wire between relay terminal H and ground. Test for less than 2.0 ohms of resistance between the relay switch terminals.
- If greater than 2.0 ohms, replace the PTO relay.