jeroensikma

Hi all!

My (year old) battery was drained because a friend who borrowed it, turned the key too far when turning the off the engine. Now I’ve been trying to jumpstart it, but when it seemed electronics where on and tried to turn the key to turn the engine on, everything shut down. Tried it again but nothing happened. Did it fry something? New battery and alternator since a about a year… thanks for any suggestions before I call a tow!

dzywicki

I have found the XJs do not like low batteries. I have not owned a car that was more sensitive to marginal batteries. First time this happened (someone left the done light on), I figured I could jump it an be on my way. I could barely get it started and it wouldn't idle. I even charged the battery on a battery tender. Would start, but wouldn't idle and wouldn't run without staying on the gas. then did some interwebs searches, came across all the threads of marginal batteries. Got a new battery and problem solved. This was on my wife's 99.
Similar story on our 98. Batteyr got marginal and I didn't even bother messing with it, got a new one and problem solved. Really aggravating.

robsjeep

1. check voltage at battery, since battery is dead, you need to do this while your known good jumper battery is hooked up If the dead battery has an internal short, it will draw down the voltage even with a good fresh jumper battery attached. if you got good voltage at battery, crank the starter, and check the voltage, if voltage drops a lot, consider that your jumper cables maybe bad or poorly connected.
the battery maybe so dead that it is taking all the juice from the good battery. how about disconnecting the dead battery ground connection, then jump ithe jeep with the good battery grounded the body, not the dead battery. (positive jumper wire and jeep positive cable may remain on the dead battery positive terminal) that will eliminate that possibility, that the dead battery is drawing down the good battery.

Keep in mind you must NOT disconnect a battery when the engine is running, there must always be a battery connected as otherwise in some charging system, the charging system can be damaged. so do NOT disconnect the good jumper battery while engine is running in the aforementioned case of the dead battery ground unconnected. stop engine before disconnect.
If this is case, then try to recharge battery via a charger.
if still wont take charge, hopefully you can do a warrentee exchange.

Turned the key too far.... Is the key switch broken? that is one possibility.

Was the key left on, i.e. ignition system left on all day? I know that spark coils can over heat, and fail when ignition is left on for extended periods without the engine turning, that is at least true in some older points operated cars. leave the key on to ignition like that if the distributor cam is at points open position, then the coil heats up big time after a while, which can ruin them.

good luck

Saudade

Yeah, jump starting with a really dead battery is chancy. I left one of my doors ajar so the interior light was on. Next morning nothing worked. No lights, no clicks, no buzz. When I jumped from my other car, I barely got any action/noise from the jeep. I left on the jumpers for about 10 minutes or so (no cranking), came back out and it started. Took the jumpers off and tested voltage while running, looked good. Pulled it around to my garage and put my battery charger on it. Since it was parked out on the street, my battery charger would have needed almost 100' of extension to reach. After a few hours, battery tested OK. No further trouble starting.

Just bear in mind that sometimes batteries don't come back after such a deep discharge. However, at a year old, you're still under warranty so get the battery fully tested to make sure it's OK.

By turned the key too far, I think he means the Accessory position.

jeroensikma

It had been draining for days. Luckily I was able to attach the Noco to push some energy into the battery and was able to start. Had the battery tested and was not able to hold a charge.

yes, it was accessory mode! Thanks everyone for replying!

robsjeep

When you get a new battery, get a fresh one, one with a new date code, one that is a month or less past is good, but more than a few months avoid, buy elsewhere. Some places neglect to keep them charged, and they do self discharge even on the shelf at the store, and if not recharged at least once a month, their service life maybe shortened. Letting a car battery drop below just even a bit below voltage, even thru self discharge, which can happen in a month, will result in a shortened life.

Buy a battery like you would buy fish.