Massey Ferguson 677.05 – Engine ECU: Starter Relay Low Voltage

The control module has detected an open circuit, high resistance, or insufficient voltage on the low-voltage trigger side of the starter relay circuit. When this occurs, the relay fails to bridge power to the starter motor solenoid, resulting in a 'no-crank' condition.

• 4710
• 7724S
• Interim Tier 4 (2012-2015)
• 7722S
• 7722
• 7615
• 5613
• 7720S
• 7716
• 7718
• 7726
• 7715
• 7616
• 7618
• 5608
• 4708
• 7619
• 7626
• 7726S
• 7624
• 4707
• 4709
• 7614
• 7718S
• 5610
• 7620
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 5612
• 7622
• 7720
• Tier 4 (2015-2021)
• 5611
• 7715S
• 5609
• 7724
• 5708
• 5709
• 5710
• 5711
• 5712
• 5713
• 6711
• 6712
• 6713
• 6714
• 6715
• 6716
• 6718
• 8727
• 8730
• 8732
• 8735
• 8737
• 8740

1. 1

   Verify the battery is fully charged. Check the battery terminals and the main earth/ground strap for corrosion or looseness, which can cause voltage drops.

2. 2

   Locate the starter relay in the fuse/relay box. Listen or feel for a 'click' when the ignition key is turned to the start position. If it clicks but doesn't pass current, the internal contacts are likely burnt.

3. 3

   Remove the relay and inspect the 4-pin socket. Look for moisture, dirt, or pushed-out pins. Use a multimeter to verify that the socket is receiving the trigger signal from the ignition switch/ECU.

4. 4

   Ensure the heavy cables at the starter motor and solenoid are tight and not burnt.

1. 1

   Disconnect battery

   Disconnect the negative battery cable to prevent accidental shorts.

2. 2

   Access fuse and relay panel

   Access the tractor's main electrical fuse and relay panel.

3. 3

   Identify starter relay

   Identify the starter relay (a heavy-duty 4-pin relay).

4. 4

   Remove faulty relay

   Pull the faulty relay straight out of its socket.

5. 5

   Clean socket terminals

   Clean the socket terminals with electrical contact cleaner if any farm dirt or moisture has breached the sealed housing.

6. 6

   Install new relay

   Plug the new direct-replacement 70-amp relay firmly into the socket (no wire splicing is required).

7. 7

   Reconnect battery

   Reconnect the negative battery cable.

8. 8

   Verify repair

   Turn the key to verify the tractor cranks. The Engine ECU should move the 000677.05 code to an inactive state, which can then be cleared.