Programmable Relay Control Module (PRCM) Caterpillar

Many of the troubleshooting procedures require an inspection of the 40-pin connector for the PRCM. A complete inspection of various terminals that are crimped should also be performed. Do the following steps in order to test an electrical connector or test a terminal that is crimped. If a faulty connection is found, repair the connection. Return to the original troubleshooting procedures and recheck the connections. Continue with the troubleshooting procedure.

Note: Avoid unnecessary disconnecting and connecting of the connector halves in order to troubleshoot system diagnostic codes. This practice can cause the connector contacts within the connector to wear out prematurely.

1. Check the hex screw connector. Make sure that the 40-pin connector on the rear of the PRCM is aligned and seated properly. Make sure that the hex screw connector is tight. Any unused pin locations in the 40-pin connector should be plugged in order to keep out dirt, water and other contaminants.

2. Each wire should be given the 10 pound pull test. Each connector contact and wire should easily withstand ten pounds of pull and the wire will remain within the connector body. This test ensures that each wire and connector contact was crimped properly. The test also ensures that the connector contact was inserted into the connector body completely. Perform repair, as needed. Use the 1U-5804 Crimp Tool when you are replacing the contacts of the connector. The contact and the crimp tool needs to match the proper wire gauge in order to ensure that the contact is crimped properly. Connector contacts should always be crimped onto the wire, never soldered.

   Note: Do the 10 pound pull test for the insulated terminals on any of the terminal strip connections. When you replace the terminals, use the proper crimping tool and use the proper techniques for the type and the brand of terminal. Use a properly sized terminal for the wire gauge. Spade terminals and ring terminals may be soldered to the wire for an improved electrical connection.

3. Visually inspect all wiring. Look for wires that are worn or wires that are scraped. Check for a pinched harness or a damaged harness.

4. Visually inspect connectors and crimp terminals. Verify that connector contacts within the connectors are not corroded or damaged. Verify proper alignment of connector contacts and location of connector contacts within the connector. Verify that the two connector halves are seated and locked together.

   Note: Check all terminals for corrosion and inspect the terminals for damage. Wiggle each wire on a terminal. The bare wires that are located at the open end of the terminal barrel should be tight. Check the tightness of the screws on the terminal strips. Perform repair, as needed.

5. Check individual connector contacts. This is especially important for intermittent problems. When you are using a new connector contact, insert this contact into each of the mating connector contacts. Check for a snug fit between the mating connector contacts. Repeat this procedure for the other connector by using a new connector contact of the correct type.