Electrical Connector - Diagnosis and Repair
88subaru07NUMBER 07-38-88
DATE 10-12-88
APPLICABILITY ALL SUBARU VEHICLES
SUBJECT: ELECTRICAL CONNECTOR DIAGNOSIS AND REPAIR
This Service Bulletin is for your information only.
When performing an electrical diagnostic check on the Subaru vehicle, the importance of good electrical connections should not be overlooked. This is especially true in instances where a condition is only experienced intermittently.
Start your diagnosis by first confirming component part operation in order to eliminate as many normally operating parts as possible. Use information found in the Electrical System Technicians Reference Booklet, Service Manual, and the newly introduced Select Monitor. Should any circuit remain suspicious after a normal diagnosis investigation, a check of the electrical connectors including a sliding resistance test is required.
The sliding resistance test consists of removing a metal terminal from its plastic housing, placing it in its respective mate, and physically measuring how tightly the two terminals fit together. These terminals must fit together tightly to properly conduct and survive the vibration and temperature extremes encountered in today's automobile environment.
A tool assortment is now available that will enable you to service the various types of electrical connectors used on all the Subaru vehicles from 1983 to date. The tools consist of the Connector Remover Kit, a pair of special crimping pliers, and an A and B replacement terminal end assortment. A description of each tool and its use follows. The tools are available through normal parts channels under the indicated part numbers.
Connector Remover Kit P/N SOA636415
Crimping Pliers P/N SOA475T100
Terminal End Assortment A P/N 81072GA140
Terminal End Assortment B P/N 81072CA150
FIGURE 1 - DOCUMENT INCLUDED WITH REMOVER KIT:
Connector Remover Kit P/N SOA636415 This tool consists of a pin vise handle and four remover inserts. Each insert will service a different type or types of connectors used throughout the vehicle. The inserts are also available separately should replacement be necessary.
FIGURE 2 - TOOL UNLOCKING TERMINAL:
It is not necessary to be able to identify all the different types of terminals in order to successfully use the tool. It is more important to understand the characteristics of the metal terminals and how they are secured into the plastic housing connector. All terminals are removed by inserting the tool into the front of the housing (not the wire side) and depressing a lock tab located on either the metal terminal or the housing.
FIGURE 3 - ECS TERMINAL REMOVAL:
Use of these tools on some of the more popular terminals is illustrated below.
The ECS, MCA, and BS terminals are commonly found under the hood in barrel connectors.
FIGURE 4 - DLI TERMINAL REMOVAL:
The DLI connector can be found at the control unit and contains female pin terminals.
FIGURE 5 - MIC TERMINAL REMOVAL:
The MIC connector can be found at multipin connector locations.
FIGURE 6 - PLC TERMINAL REMOVAL:
The PLC connector can be found at the control unit.
FIGURE 7 - CRIMPING TOOL:
Most terminal ends can be tightened or closed up to give a tighter grip. Should a terminal end require replacement, crimping tool P/N SOA475T100 will be required along with a replacement metal terminal. The crimping tool has a unique squared off jaw design and must be used exclusively when servicing the terminal ends.
Terminal end assortment kits P/N 81072GA140 (Assortment A) and P/N 81072GA150 (Assortment B) are available and contain a quantity of replacement ends. It is recommended that each dealer have both assortment kits A and B as well as the crimping pliers and Connector Remover Kit.
FIGURE 8 - CRIMPING SEQUENCE:
Included with the pliers is a brochure that describes the crimping procedure. These steps include:
1) Starting with a squared off wire end, strip off about 1/32" more insulation than the terminal barrel length.
2) Orient the wire and terminal correctly and crimp.
3) Perform a mechanical crimp (on the insulation) if the terminal end is so equipped.
4) Take care not to damage the stabilizer portion of the terminal.
FIGURE 9 - SLIDING RESISTANCE TEST:
A sliding resistance test can also be performed at the control unit where it is impossible to get at the other end to confirm continuity. An old discarded control unit can be used as a tool. Carefully disassemble the control unit and remove the pin terminals. The pin terminals can now be inserted into the plastic connector and the sliding resistance can be felt. One control unit can provide enough pin terminals for several technicians.
FIGURE 10 - CORRECT TEST PROBING:
Be aware when performing a sliding resistance or other electrical test that incorrectly using a pointed tip tester or probe can inadvertently aggravate the condition or damage electrical connections. Always probe the back (wire) side of the terminals when testing a connector to avoid opening up the terminal and loosening its grip or unseating the terminal from its housing.
No electrical diagnosis procedure would be complete without a check of all engine and body grounds. Just because a ground connection is tight doesn't ensure good continuity. Grounds that are suspect should be removed and checked for corrosion build up.