RAM 2500 Truck 2WD V8-5.7L (2008)
Main Relay (Computer/Fuel System): Testing and Inspection
Fig.1 ASD And Fuel Pump Relay Terminals-Type 1
Fig.2 ASD And Fuel Pump Relay Terminals-Type 2
The following description of operation and tests apply only to the Automatic Shutdown (ASD) and fuel pump relays. The terminals on the bottom of
each relay are numbered. Two different types of relays may be used, or.
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Terminal number 30 is connected to battery voltage. For both the ASD and fuel pump relays, terminal 30 is connected to battery voltage at all
times.
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The PCM grounds the coil side of the relay through terminal number 85.
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Terminal number 86 supplies voltage to the coil side of the relay.
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When the PCM de-energizes the ASD and fuel pump relays, terminal number 87A connects to terminal 30. This is the OFF position. In the OFF
position, voltage is not supplied to the rest of the circuit. Terminal 87A is the center terminal on the relay.
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When the PCM energizes the ASD and fuel pump relays, terminal 87 connects to terminal 30. This is the ON position. Terminal 87 supplies
voltage to the rest of the circuit.
The following procedure applies to the ASD and fuel pump relays.
1. Remove relay from connector before testing.
2. With the relay removed from the vehicle, use an ohmmeter to check the resistance between terminals 85 and 86. The resistance should be 75 ohms
