GMC T-Series 2007 Owner's Manual page 283

Relay Block B
Relay Block B
Air Conditioning Condenser
1
(If Equipped)
Air Conditioning Compressor
2
(If Equipped)
3 Heater Fan
4 Ignition (Accessory)
5 Ignition (1)
6 Ignition (2)
7 Auxiliary
8 Horn
9 Ignition (3)
10 Dome Lamp (If Equipped)
11 Exhaust Brake (If Equipped)
Power Take-Off Control
12
(If Equipped)
Usage
283