There are four relay blocks in the vehicle:
Relay Block A
Relay Block B
Relay Block C
Relay Block D (Not Shown)
Relay Block A
Relay Block A | Usage |
|---|---|
1 | Power Window (If Equipped) |
2 | Power Main (ECU) |
3 | High Beam |
4 | Lighting |
5 | Lighting (Low, High) |
6 | Trailer Turn Signal (Left Headlamp) |
7 | Taillamp |
8 | Marker Lamp (Tractor Only) |
9 | Trailer Turn Signal (Right Headlamp) |
Relay Block B
Relay Block B | Usage |
|---|---|
1 | Air Conditioning Condenser (If Equipped) |
2 | Air Conditioning Compressor (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 | Starter Cut |
12 | Power Take-Off Control (If Equipped) |
Relay Block C
Relay Block C | Usage |
|---|---|
1 | Parking Brake |
2 | Daytime Running Lamps (DRL) On (Engine Run) |
3 | Daytime Running Lamps (DRL) Off (Parking) |
4 | Parking Lamps/Daytime Running Lamps (DRL) |
5 | Fuel Filter (Heated Fuel) |
6 | Stop Lamp |
Relay Block D
Relay Block D | Usage |
|---|---|
1 | Neutral (Medium Duty Transmission) |
2 | Back-up Lamp (Reverse) (Medium Duty Transmission) |
