2005 no power full charge battery

[WestlakeOH]

My 2005 KJ recently developed an odd problem. The jeep wouldn't start a few mornings even though there is a months old battery there was absolutely now power (no lights, horn, radio, etc) - nothing happened with turn of the ignition key. This is my daughters car so I thought she may have left something on overnight so I jumped the battery, the car started and she drove it with no issues for a couple of days. Yesterday morning she attempted to start and once again, no power. I decided to put a trickle charger on the battery and left it cycle till this morning. The charger showed a completely charged battery but when I went to start the car - nothing, no interior power, no horn, no start. Oddly, I was able to jump start the car and it ran fine. I took it down to Autozone to have the battery and starter checked and both were fine. Right now the car starts just fine. I did check the battery post connectors and they were tight and clean.

What could be causing the random "no power" issue when I have a fully charged battery and apparently good starter. and why can I jump start the car with cables but not off the fully charged batter?

 

[GunnerSchenck]

How are the terminal connections? Clean and tight?
When you try and turn it over when there's no power, how do you know the battery is fully charged? And when you try to do so, do you get a ticking or nothing at all?

 

[tjkj2002]

Have ran into similar issues on other vehicles.

The battery post/terminals may look clean but a thin layer of corrosion can form between the terminal and post.Take the terminal ends off the battery and use a battery brush to clean the posts and the inside of the terminals very good and see if it happens again.

Alos could be a bad battery,internal short.

 

[JasonJ]

You need to put a voltmeter on that battery.... check voltage coming off of the charger (after resting for an hour). Should be 12.65v or so, but not less than 12.45-12.50v.

Keep voltmeter connected and in view when cranking, and see what happens to the voltage when you move key to START position...

Start there and report back. But I too am leaning towards faulty cable connections. They may appear good and clean on the outside, but it's inside, between the terminal and battery post that matters.

 

[WestlakeOH]

How are the terminal connections? Clean and tight?
When you try and turn it over when there's no power, how do you know the battery is fully charged? And when you try to do so, do you get a ticking or nothing at all?

I had installed a new battery on this jeep just two months ago and didn't think there would be issues with the post/terminal connections. so a week or so ago when the jeep, once again, had no power, I cleaned the negative post and terminal, re-attached, and the jeep powered and started right up. It ran fine for a week until this past weekend when my daughter took the jeep out of town and the no-power symptoms re-appeared. She had to get the jeep jump started twice after turning the engine off. When she got home the same no-power situation when I tried to start the jeep. I did have the battery and starter tested a week ago at Autozone. If not the battery or the starter, could it be in the cable itself or a ground issue? Once the car is jumpstarted, it works fine. Also, a couple of times, the interior lights and power locks work up till I tried to start the jeep then it went dead. weird

 

[WestlakeOH]

You need to put a voltmeter on that battery.... check voltage coming off of the charger (after resting for an hour). Should be 12.65v or so, but not less than 12.45-12.50v.

Keep voltmeter connected and in view when cranking, and see what happens to the voltage when you move key to START position...

Start there and report back. But I too am leaning towards faulty cable connections. They may appear good and clean on the outside, but it's inside, between the terminal and battery post that matters.

would this be a check for an internal battery short?

 

[CzarKJ]

You had the battery and starter tested. But what about the alternator? Did you clean the terminals like Tjkj stated?

 

[JasonJ]

would this be a check for an internal battery short?

This is a check to see the state of charge of the battery after the trickle charge (you just HAVE to be certain of the batt voltage before doing anything, just in casae). But this is also to check and see if the vehicle is actually doing anything when you turn the ignition to the various positions.

If the voltage of the battery starts to go down, there is something turning on, which is preferable. If when trying to crank it the voltage goes WAY down (but not below 10.0v, that indicates a weak/bad battery, regardless of battery test), then that indicates that the starter is drawing power from the battery in an attempt to start the engine.. but clearly if it is not cranking over, then perhaps the battery is bad and not able to supply enough power, or the starter is defective and drawing way too much power for what it's supposed to.

If the voltage doesn't change at all, then you have a wiring/cabling issue of some sort. Might be batt terminals, might be in the ignition switch, but certainly if not the batt terminals, it'll be in the ignition switch CIRCUIT.

 

[justjeeps]

My 2005 KJ recently developed an odd problem. The jeep wouldn't start a few mornings even though there is a months old battery there was absolutely now power (no lights, horn, radio, etc) - nothing happened with turn of the ignition key. This is my daughters car so I thought she may have left something on overnight so I jumped the battery, the car started and she drove it with no issues for a couple of days. Yesterday morning she attempted to start and once again, no power. I decided to put a trickle charger on the battery and left it cycle till this morning. The charger showed a completely charged battery but when I went to start the car - nothing, no interior power, no horn, no start. Oddly, I was able to jump start the car and it ran fine. I took it down to Autozone to have the battery and starter checked and both were fine. Right now the car starts just fine. I did check the battery post connectors and they were tight and clean.

What could be causing the random "no power" issue when I have a fully charged battery and apparently good starter. and why can I jump start the car with cables but not off the fully charged batter?

My old 03 had an issue with the ignition switch, actually for a while I thought is was handy because I could pull the keys out and let it warm up locked...but that turned into a battery killing problem because the key could be pulled out when the switch was not quite lined up to off after you parked. The result was the little LED lights in the knobs, windows, door switch were being left on. You could only notice this in the dark. Long story short that little issue cost over $200 for CAA to come out and replace the battery. It was 4 degree F so I was So Happy My Wife Flexed Her CAA account for me....The new battery went dead also thats when I decided to go out in the dark and behold I could see the led lights after charging the new battery back up...

I just had to be sure the key was aligned up in the ignition switch correctly before removing it / with engine off...Expensive lesson.

Bottom line the ignition switch was bad and it was leaving the accessories but with everything turned off you could not notice the little led in side the buttons unless it was dark. O be sure you turn the AC/Heater knob to off as well.

cheers