821300 20 Mercury SCREW, (M6 x 20)

Illustration 1 g01091839
MS connectors
The MS connectors have a metal housing. The pins and the sockets are soldered to the electrical wires. The solder connections are usually protected by a chemical potting which prevents access to the solder point.
Illustration 2 g01091843
Deutsch connectors
Deutsch connectors have a plastic housing. The pins and the sockets are crimped onto the electrical wires. The connector has a locking mechanism in order to hold the pins and the sockets. These connectors are repairable without cutting the wires.
Illustration 3 g01092021
70-pin connector for the ECM
Use the following test steps in order to thoroughly inspect the connectors and determine if the connectors are the cause of the problem.Test Step 1. Check the Connectors
Always set the engine control to the OFF/RESET mode before you inspect electrical conductors. Remove the electrical power from the engine.
For the MS connectors, make sure that the receptacle is turned fully in the clockwise direction. Check that the threading is properly aligned and securely mated.
For the Deutsch HD connectors, make sure that the plug and the receptacle are aligned properly with the index markings. Make sure that the receptacle is turned fully in the clockwise direction. Verify that the receptacle is clicked into the locked position. Make sure that the two halves cannot be pulled apart.
For the Deutsch DT style, make sure that the orange wedge is used in order to lock the pins. Check that the receptacle has clicked into the locked position. Make sure that the two halves cannot be pulled apart. Expected Result:All connectors are properly mated and free of damage.Results:
OK - Proceed to test step 2.
Not OK - Repair: Repair the connectors and/or replace the connectors. Reconnect all of the connectors.STOPTest Step 2. Check the Allen Head Screw on the ECM Connector
Ensure that the Allen head screw is properly tightened. Be careful not to overtighten the screw and break the screw.
When you connect the 70-pin connector to the Electronic Control Module (ECM), do not exceed 6 1 N m (55 9 lb in) of torque on the screw. Expected Result:The ECM connector is secure and the Allen head screw is properly torqued.Results:
OK - Proceed to Test Step 3.
Not OK - Repair: Repair the connector or replace the connector, as required.Verify that the repair eliminates the problem.STOPTest Step 3. Perform a Pull Test on Each Wire Connection
Each terminal and each connector should easily withstand 45 N (10 lb) of pull and each wire should remain in the connector body. This test checks whether the wire was properly crimped in the terminal and whether the terminal was properly inserted into the connector.
The DT connectors use an orange wedge to lock the terminals in place. Ensure that the orange wedge is not missing and that the orange wedge is installed properly on the DT connectors. Note: Always crimp the terminals onto the wires by using a Crimp Tool. Do not solder terminals. Use the 1U-5804 Crimp Tool.Expected Result:Each terminal and each connector easily withstands 45 N (10 lb) of pull and each wire remains in the connector body.Results:
OK - Proceed to Test Step 4.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 4. Monitor the Electronic Service Tool While the Wiring and the Connectors Are Being Pulled
There is a strong electrical shock hazard when the crankshaft is rotating. Do not touch wires that are associated with the ignition transformer circuit when the engine is cranking or running.
If there is an active diagnostic code that pertains to the circuit, perform the following steps:
Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine.
Connect the Caterpillar Electronic Technician (ET) to the service tool connector on the terminal box.
Restore the electrical power to the engine. Set the engine control to the "STOP" mode. Then start the engine. Run the engine under normal operating conditions.
Monitor the "Active Diagnostic Code" screen on Cat ET while you pull on all harnesses and connectors for the circuit with the active code. If the harness is being pulled and the active diagnostic code disappears, there is a problem in the wiring or the connector.
If there are no active diagnostic codes that pertain to the circuit, perform the following test:
Run the engine under normal operating conditions.
Monitor the "Display Status" screen on Cat ET while you pull on all harnesses and connectors for the circuit. If the harness is being pulled and the reading changes erratically, there is a problem in the wiring or the connector.
If there are no active diagnostic codes and there are complaints about intermittent changes in speed or power cutouts, perform the following test:
Run the engine under normal operating conditions.
Listen for speed burps or power cutouts while the wiring and/or the connectors are pulled. If the harness is being pulled and the engine has a speed burp or a power cutout, there could be a problem in the wiring or the connector.Expected Result:The problem appears to be external to the harnesses and connectors. Pulling on the harness and the connectors has no effect on the active diagnostic code, component status, or engine performance.Results:
OK - Proceed to Test Step 5.
Not OK - Repair: Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine. Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 5. Check Wires for Nicks or Abrasion in the Insulation
Set the engine control to the "STOP" mode. Allow the engine to coast to a stop.
Set the engine control to the "OFF/RESET" mode. Remove the electrical power from the engine.
Carefully inspect each wire for signs of abrasion, nicks, or cuts. The following areas are likely locations:
Places with exposed insulation
Points with wiring that rubs against the engine
Places with wiring that rubs against a sharp point
Check all of the hold down clamps for the harness in order to verify that the harness is properly clamped. Also, check all of the hold down clamps in order to verify that the harness is not compressed by the clamps. Pull back the harness sleeves in order to check for flattening