I have an 88 Jeep Cherokee with 260K. Yesterday the engine died while in transit. When turning the key, there is no cranking to start the engine, and none of the accessories work (radio, horn, turn signals). It's as if there is no power. The headlights and hazzards work just fine though. Nice and bright.
I checked the battery and all is well there as expected since the headlights work. I replaced the ignition switch module thinking that could be the only culprit, but still nothing.
Hmmm.... One common point for the power is off the starter solenoid/relay on the fender by the battery. There you will find the main battery power cable along with several fuse link wires off the same bolt.
These fuse link wires power up the different sections of the wiring harness. They are loops on one end at the bolt with about 8" of soft fat wire and a big tube crimp connector where they joint the harness. These 'can' wear out or blow if something shorts out. Look for burn marks on the insulation or pull gently on them to see if they flop around.
Having only headlights with power almost implies a blown fuse link wire.
'Maybe' a dead engine ground connection or a dead body ground connection could be the issue. The body ground is a mesh strap that runs from the back of the engine head up to the firewall. When this goes, it kills the ignition, but not usually the starter power.
The starter power can be stopped if the negative cable is dirty at the engine block. I test this and the body ground by using a booster cable from the battery negative to the engine block and then to the body to see if this makes any difference.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Looks like the negative battery cable was in pretty bad shape. Replaced and able to connect the broken fuse link without it burning more. Braided ground wire was still very nicely intact.
Now I am unable to determine the fusible link gauge used for this model. Have green and orange coated wires for the links, so not sure if they indicate different gauges. So far all I have found at the local parts shop is black fuse link wire.
Once I get this I assume some resin core solder should do the trick with a good tape job. I also have liquid wire coating that I could use that may work better.
You should be able to get fuse wire in several guages indicated by the color code - try a better parts shop. Don't even think about soldering fuse links! Get a decent crimper and appropriate size fittings for the ends. Crimp new lugs on the ends and go with it. If I feel like there is a significant corrosion problem I might dunk the ends in a plastic/rubberized paint solution - remember that there is probably an open hole on the connectospade side of the crimp as well - but I rarely mess with it. I did that on a marine application once and it didn't make too much difference over time.
You can't solder fuse link wires, it will damage the properties of it. They sell waterproof crimp connectors these days, you just heat them after crimping.
The ignition fuse link is a 14 ga one protecting the 10 ga wires.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: N>
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