Upgrading The Main Igniton Wire


All Jeepsters have serious electrical design problems. One is the main, red positive wire that begins at the starter's positive post, then goes to the alternator's positive terminal, across the firewall to the hot side of the 30 amp relay, which is located on the drivers side kick panel, and ends at the ignition switch. This wire is not fused. Another is, this main wire is too small a gauge wire.

The wire for 1966/'71 Jeepsters is only 12 gauge, while the 1972-73 models are 10 gauge, never the less, both end up at the ignition switch terminal labeled BATT. The wire could be either a red wire with a white strip or a solid red wire. Disconnect the negative battery cable and remove the ignition switch and look carefully for melted terminal plugs or burned, brittle or bare wiring. Check if the wire terminals are still good and look for hot marks on the ignition switch too.

The main wire can break off at the crimped part of the female spade terminal, then drop down, short out and cause a fire. If evidence of bad ignition wiring or switch is noticed, have it fixed! Best bet... upgrade the wiring loom with a fuse panel.

To help prevent your Jeepster from being nuked, you can splice in a "fusible link". First determine what gauge wire your Jeepster has, 12 or 10 gauge. Then head to a parts store and ask where the fusible wire or links are.

The rule is that fusible wire should be TWO gauges smaller. 12 gauge wire uses 16 gauge fusible wire and 10 gauge wire uses 14 gauge fusible wire. There are different types of fusible wire/link but chose to buy a bulk roll of it. Purchase an eyelet wire terminal that will fit the alternator terminal post, and also a butt connector. Both should be the heat shrink, (waterproof) style connectors.

Once home, disconnect the negative battery cable, then find the RED wire located behind the alternator that heads across the intake manifold, to the wire loom plug, located on the fire wall.

Cut the red wire about five inches from the end, and strip about a 1/4" inch of insulation off its end. Next, cut a six inch section of the fusible wire, strip both ends, crimp on the butt/eyelet terminals on and then shrink them up with a hair dryer. Now, push the butt connector on the red wire, crimp it and shrink it also with the hair dryer.

All that is left is to re-tape the loom, connect the red wire back up to the alternator and hook the negative battery cable up again. This should prevent your Jeepster from ending up in the junkyard due to fire.


NOTE: If the Jeepster has the 12 gauge wire, you can upgrade it to 10 gauge and then install a fusible link.


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