See Figure 1
A fusible link is a short length of insulated wire, integral with the engine compartment wiring harness. It is several wire gauges smaller than the circuit it protects and is located in-line with the positive terminal of the battery.
When heavy current flows or when a short to ground occurs in the wiring harness, the fusible link burns out and protects the alternator or wiring. Production fusible links are color coded:
Replacement fusible link color coding may vary from production link color coding.
See Figure 2
- Determine which circuit is damaged, its location and the cause of the open fusible link. If the damaged fusible link is one of three fed by a common No. 10 or 12 gauge feed wire, determine the specific affected circuit.
- Disconnect the negative battery cable.
- Cut the damaged fusible link from the wiring harness and discard it. If the fusible link is one of three circuits fed by a single feed wire, cut it out of the harness at each splice end and discard it.
- Identify and procure the proper fusible link and butt connectors for attaching the fusible link to the harness.
To repair any fusible link in a 3-link group with one feed:
- After cutting the open link out of the harness, cut each of the remaining undamaged fusible links close to the feed wire weld.
- Strip approximately 1 / 2 in. (13mm) of insulation from the detached ends of the two good fusible links. Then insert two wire ends into one end of a butt connector and carefully push one stripped end of the replacement fusible link into the same end of the butt connector, then crimp all three firmly together.
Care must be taken when fitting the three fusible links into the butt connector, as the internal diameter is a snug fit for three wires. Make sure to use a proper crimping tool. Pliers, side cutters, etc. will not apply the proper crimp to retain the wires and withstand a pull test.
- After crimping the butt connector to the three fusible links, cut the weld portion from the feed wire and strip approximately 1 / 2 in. (13mm) of insulation from the cut end. Insert the stripped end into the open end of the butt connector and crimp very firmly.
- To attach the remaining end of the replacement fusible link, strip approximately 1 / 2 in. (13mm) of insulation from the wire end of the circuit from which the blown fusible link was removed, and firmly crimp a butt connector or equivalent to the stripped wire. Then, insert the end of the replacement link into the other end of the butt connector and crimp firmly.
- Using rosin core solder with a consistency of 60 percent tin and 40 percent lead, solder the connectors and the wires at the repairs and insulate with electrical tape.
- To replace any fusible link on a single circuit in a harness, cut out the damaged portion, strip approximately 1 / 2 in. (13mm) of insulation from the two wire ends and attach the appropriate replacement fusible link to the stripped wire ends with two proper size butt connectors. Solder the connectors and wires, then insulate with tape.
- To repair any fusible link which has an eyelet terminal on one end such as the charging circuit, cut off the open fusible link behind the weld, strip approximately 1 / 2 in. (13mm) of insulation from the cut end and attach the appropriate new eyelet fusible link to the cut stripped wire with an appropriate size butt connector. Solder the connectors and wires at the repair and insulate with tape.
- Connect the negative battery cable to the battery and test the system for proper operation.
Do not mistake a resistor wire for a fusible link. The resistor wire is generally longer and has print stating, "Resistor: don't cut or splice.''