shadowhunter22
Active Member
- Thread starter
- #1
Hi everyone, I've been lurking here for a while but first main post. My JLU Sport S is having some battery issues and I'm fighting with the dealership to replace my auxiliary battery, and would love for anyone to point out where I might be in the wrong or missing something. It's a long one, feel free to cut to the summary. So here's the story:
This past Friday morning (8 March), started driving the Jeep to work, some error message pops up on the console; don't remember it exactly, but it was something about the ESS needing serviced, vehicle will shut down soon, drive safely. So pulled over, shut down, waited a minute then tried to start up again. Entire dash started freaking out, lights going off, wipers going, all that noise. From others' posts here, this seems to have happened when the auxiliary battery was too low/dead (I have some ideas for how it drained, but not relevant to the fix). After a few attempts, all power went out entirely.
Had someone come try to jump me using a battery pack; he did a quick voltmeter reading on the main battery and it was around 12.4 I believe. The jump didn't work (this was before I had read the posts about how a battery pack isn't sufficient to get both the aux and main battery charged enough to jump). So, while getting towed to a nearby dealership, I read a few posts here that people had success using a donor vehicle and letting the batteries charge for a few minutes. I mention that to the mechanic, who of course immediately blows me off, says that's probably not the issue, and they'll have to keep it for a few hours. I tell him that the main battery tested fine, and everything is pointing to a drained/dead aux battery, but all that fell on deaf ears.
Over the weekend typical service dept shenanigans ensue (zero contact, try to find out what they've tried already but nothing is actually in the system, just word of mouth from one dude to another, never got to talk to anyone who had actually touched my Jeep, good times). Did learn that they replaced the main battery (even though that one was totally fine...) and the various techs I talked to "think" they had tried to charge the batteries (which I don't believe, because I see where it's been parked all weekend and that just doesn't seem likely). Ask about the aux battery, get a deer in the headlights look. A not-insignificant part of me thinks they don't even know the JLs have an aux battery....
Anyway, called Monday morning for an update, they say they still can't get any power to the Jeep whatsoever so they need their electrical tech to look at it. I ask if they've tried swapping the aux battery..."yea I think so." They promise to call me back soon. Several hours go by, so I head to the dealership with my buddy's truck who has a healthy battery, jumpers, and my own voltmeter. Test main battery, healthy 12.7 or so. Disconnect the terminals to test the aux battery...4.5 volts. So we try to "chump start" it as others have mentioned, connecting the positive cable to the N1 terminal. After 10 minutes or so, success! Lights come on, I'm able to start, all seems well. Console says voltage is between 14.0-14.3 volts, but this is while jumpers are still attached, not sure if alternator has taken over.
As soon as we pull the jumpers, engine dies and things go back to Friday morning (dash freaking out and whatnot). Recheck aux voltage, only up to about 4.7 volts. Debated trying to sit there letting it charge longer, but I think the voltage is low enough that replacing it is the right call. This whole time we've been trying to get the service manager over to us (seriously we sat there for over an hour screwing around with a vehicle on their lot, at they didn't even seem to care), eventually get fed up and go to talk to them. Of course the manager is nowhere to be found, so I tell one of the other techs about what we were able to do (i.e. get power to the vehicle long enough to start, which they hadn't been able to do yet), and that I'm 99% sure replacing the aux battery is the solution.
Call this morning (Tuesday), of course none of that info got passed to my "assigned" tech (who also has not personally talked to me at all this whole time, but that's beside the point), they keep regurgitating "we replaced the (main) battery on Friday and it's still not responsive." It's too early to drink but I may start anyway.
In summary....
- Main battery has checked out good (though they replaced it anyway)
- Aux battery is not good (around 4.5 volts)
- When donor vehicle is connected to N1 terminal, power flows allowing engine to start (but not sure if alternator is taking over)
- Jeep dies again when jumper cables are removed, eventually aux seems entirely dead
Basically, all of the electrical pathways seem to be fine, since they work when a donor vehicle is supplying power. The issue is either (maybe both) the aux battery is dead, or an issue with the alternator since it's not taking over. Small chance it could be an IBS issue but that doesn't seem likely.
Should I keep pushing the dealership to replace the aux battery before anything else? If that doesn't work, then the second most likely issue is the alternator...but it seems dumb to jump to replacing that before trying a new aux battery.
Any feedback/spears/tips for not losing my mind would be much appreciated. I'm already in touch with the JeepCares team here but I'm curious what all the members have to say.
This past Friday morning (8 March), started driving the Jeep to work, some error message pops up on the console; don't remember it exactly, but it was something about the ESS needing serviced, vehicle will shut down soon, drive safely. So pulled over, shut down, waited a minute then tried to start up again. Entire dash started freaking out, lights going off, wipers going, all that noise. From others' posts here, this seems to have happened when the auxiliary battery was too low/dead (I have some ideas for how it drained, but not relevant to the fix). After a few attempts, all power went out entirely.
Had someone come try to jump me using a battery pack; he did a quick voltmeter reading on the main battery and it was around 12.4 I believe. The jump didn't work (this was before I had read the posts about how a battery pack isn't sufficient to get both the aux and main battery charged enough to jump). So, while getting towed to a nearby dealership, I read a few posts here that people had success using a donor vehicle and letting the batteries charge for a few minutes. I mention that to the mechanic, who of course immediately blows me off, says that's probably not the issue, and they'll have to keep it for a few hours. I tell him that the main battery tested fine, and everything is pointing to a drained/dead aux battery, but all that fell on deaf ears.
Over the weekend typical service dept shenanigans ensue (zero contact, try to find out what they've tried already but nothing is actually in the system, just word of mouth from one dude to another, never got to talk to anyone who had actually touched my Jeep, good times). Did learn that they replaced the main battery (even though that one was totally fine...) and the various techs I talked to "think" they had tried to charge the batteries (which I don't believe, because I see where it's been parked all weekend and that just doesn't seem likely). Ask about the aux battery, get a deer in the headlights look. A not-insignificant part of me thinks they don't even know the JLs have an aux battery....
Anyway, called Monday morning for an update, they say they still can't get any power to the Jeep whatsoever so they need their electrical tech to look at it. I ask if they've tried swapping the aux battery..."yea I think so." They promise to call me back soon. Several hours go by, so I head to the dealership with my buddy's truck who has a healthy battery, jumpers, and my own voltmeter. Test main battery, healthy 12.7 or so. Disconnect the terminals to test the aux battery...4.5 volts. So we try to "chump start" it as others have mentioned, connecting the positive cable to the N1 terminal. After 10 minutes or so, success! Lights come on, I'm able to start, all seems well. Console says voltage is between 14.0-14.3 volts, but this is while jumpers are still attached, not sure if alternator has taken over.
As soon as we pull the jumpers, engine dies and things go back to Friday morning (dash freaking out and whatnot). Recheck aux voltage, only up to about 4.7 volts. Debated trying to sit there letting it charge longer, but I think the voltage is low enough that replacing it is the right call. This whole time we've been trying to get the service manager over to us (seriously we sat there for over an hour screwing around with a vehicle on their lot, at they didn't even seem to care), eventually get fed up and go to talk to them. Of course the manager is nowhere to be found, so I tell one of the other techs about what we were able to do (i.e. get power to the vehicle long enough to start, which they hadn't been able to do yet), and that I'm 99% sure replacing the aux battery is the solution.
Call this morning (Tuesday), of course none of that info got passed to my "assigned" tech (who also has not personally talked to me at all this whole time, but that's beside the point), they keep regurgitating "we replaced the (main) battery on Friday and it's still not responsive." It's too early to drink but I may start anyway.
In summary....
- Main battery has checked out good (though they replaced it anyway)
- Aux battery is not good (around 4.5 volts)
- When donor vehicle is connected to N1 terminal, power flows allowing engine to start (but not sure if alternator is taking over)
- Jeep dies again when jumper cables are removed, eventually aux seems entirely dead
Basically, all of the electrical pathways seem to be fine, since they work when a donor vehicle is supplying power. The issue is either (maybe both) the aux battery is dead, or an issue with the alternator since it's not taking over. Small chance it could be an IBS issue but that doesn't seem likely.
Should I keep pushing the dealership to replace the aux battery before anything else? If that doesn't work, then the second most likely issue is the alternator...but it seems dumb to jump to replacing that before trying a new aux battery.
Any feedback/spears/tips for not losing my mind would be much appreciated. I'm already in touch with the JeepCares team here but I'm curious what all the members have to say.
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