Betty Cress Bishop

my son has a 98 jeep cherokee sport with the straight 6. Last night he was putting his window up and forgot to turn the ignition switch off, killing the battery. (distracted teen?) an older gentleman offered to give a jump but when they tried, he said the cables were really hot so they disconnected them. Another man with a better pair of cables then tried to jump it. They said it tried to turn over but never started. I'm thinking battery was so dead it needed to be charged more. /Because it was raining really hard they closed up and came home.

Later, I went back with them and used another battery out of my SUV which has been sitting a couple months. The battery was good it just needed a quick jump from sitting so long. I had a broken clamp and it wasn't charging properly. anyway, When they hooked the cables, the poor young bucks reversed the cables. I didn't know this and fired up the vehicle doing the jumping. Immediately the cables, especially the negative, started smoking and they yelled to shut it off. It completely melted the cable on the negative side.

Got a good strong pair of cables and hooked it up correctly myself but now there's nothing. Even with the cables attached and other vehicle running, not even the dome light comes on. No clicks, nada. I'm thinking best case scenario a fusible link blew somewhere. Worst case, it blew the electrical system. I'm hoping that since he never turned on the ignition switch it didn't do that much damage.

Its like there is an open circuit, like a blown fuse, or bad ground and its not getting any power at all. Where on this vehicle would the fusible link be? I'm thinking follow the ground cable back. Any suggestions to make this less painful?

CCKen

there's a small cover on the front end of the Power Distribution Center (PDC) in the engine bay (holds relays and fuses).


Remove that small cover and you will see a Green wire connected to the bus bar for the PDC. That's the fusible link. The other cable should be Red, which goes to the battery positive post.


The fusible link is spliced to the B+ cable that comes from the alternator.


Remove the battery negative post connector then remove the cable from the alternator and at the PDC bus bar, then, using and Ohmmeter, check for continuity in that cable (end to end). If it reads open the fusible link is melted.


There is a possibility that the alternator and/or the PCM has been smoked by hooking up the jumper cables incorrectly.

CCKen

Pic of PDC Bus Bar connections.

Jeepin'_Aint_EZ

Best case scenario is that the fusible link did its job quickly and saved the electronics from a reverse polarity jolt. Otherwise... you'll be chasing electrical gremlins. Good Luck!

Betty Cress Bishop

I have a really bad feeling after seeing the photo. At some point someone had cut some wires on or near that box. I don't remember which but will look a take a pic of it and post it. Maybe a little bit of cowboy engineering going on? First I'll check the wire you mentioned. I do remember a red wire being cut in that area. This was before he got the jeep.

CCKen

Here's the '98 charging system wiring diagram and an image of the B+ connection at the alternator:



.

Betty Cress Bishop

fusible link saved the day! I cut out the fusible link after testing it and getting an open circuit on the multi-meter. Tested it by connecting without link and the ole girl fired right up and ran like a charm. Now, where do I get a replacement? Seems like all the parts sites know nothing about it and I'm not about to let him drive it without the fusible link. This was just a quick fix to get her home.

CCKen

You might try a junk yard. A 96-98 should fit. 99 and up has the cable w/FL but it may be a little different because alternator is different and the cable connection at the alternator may be different. Don't know for sure.


Also, try someone parting out an XJ on this forum.


You can buy fusible link on line. You need AWG 10 with a 5/16" ring terminal. The fusible link will need to be the exact length as the original and will need to be parallel connector crimped.


Go here:


http://www.whiteproducts.com/fusible-faqs.shtml


Browse through the catalog. You will see the FL kits and parallel connectors.


Check Ebay as well.

Betty Cress Bishop

thank you CCKen! While I'm thinking about it, does it matter on a Jeep if you have different size tires, like 3 235 75 15s and 1 225 75 15? I know with my explorer they have to be identical or it messes with my 4wd. Mine is auto but his is manual. I just noticed his tires when we were working on it. Of course this momma gave him hell because his front drivers side was worn really bad on the outside. What would cause that? I drove it once and it scared the hell outta me the way it wanted to go all over the place. He says its normal but I dont think so. To me its like you're constantly having to adjust the steering to the right or left. I'm used to mine where you can pretty much take your hands off the wheel n it will stay smooth n straight.

CCKen

He must have the same size tires in all four positions. No options.


Additionally, they should have about the same amount of wear on them. If necessary, move a set of equally worn tires to the front.


Use your browser to find an image of tie wear patterns and possible causes.

97grand4.0

As a licensed electrician with 40 years of wrenching, what it sounds like to me is you have a dead short in the battery cables, check underneath to see if the + is rubbing on the steering components somewhere. Anything that lights up a pair of jumper cables, twice, has to be fixed, before you have any hope of anything other than lighting up the XJ like a used Christmas tree bonfire. I had an S10 this happened to but was able to pull the bat cables off.
THEN you can worry about the fuseable link.
I'd recommend getting someone in there who knows what they're doing with a test meter and go through it.

Jeepin'_Aint_EZ

Did you happen to read any of the responses other than the original post? CCKen already took care of this one

But for the sake of conversation, the most probable reason it was heating up the first set of jumper cables was due to a small ga. wire. Cheap jumper cables are just that, cheap. They get hot fast and won't last trying to jump a battery that's as dead as dead gets, which was this case. The second time was from accidentally reversing the polarity on one end of the cables which everyone knows will heat cables up no matter what size they are. The fusible link did it's job which caused the OL condition and no action at the key. Replaced the FL and there's power again, would ya look at that.