One problem related to starter relay has been reported for the 2007 Chevrolet Avalanche. The most recently reported issues are listed below.
10/21/09- went out to start my 07 Avalanche lt3 and there was no power to anything. Aaa service was called and check the battery and it had 4. 6 amps. After attempting to charge battery it still would not start. The technician began checking fuses and removed and replaced the same starter relay switch and then it started.