Battery is draining, need help/recommendations

I've been having this problem for some time now. My battery on my 2000 XJ keeps draining when it sits for any period of time, the longer it sits the more it drains. Sitting over night won't completely drain it, but sure makes for a slow start.

When it's off, it is only pulling 30 milliamps so I am having a hard time believing it's an accessory doing it. When running the voltage meter on the dash reads 14 AMPs. I've gone through the troubleshooting and ruled out a short.

When this problem first started about 4-5 months ago, I thought it was the crap battery I bought it with, so I went out and replaced it with an Optima red top, now it's doing it with this one.

Does anyone have any ideas of what else I can check?

You could have a bad diode in the ALT, try unplugging it and see if it starts better in the morning.

I know this may be a dumb question, but I want to be clear. Unplug the battery, right?

If this works, I'm assuming I need to replace the ALT?

T

foodeewaa said:

I know this may be a dumb question, but I want to be clear. Unplug the battery, right?

If this works, I'm assuming I need to replace the ALT?

T

Click to expand...

No unplug just the ALT. all three wires

Let us know what happens.

OK, I finally was able to give this test a shot, and it didn't seem to make a difference. Battery was almost dead again in the morning, but will still start...bearly.

Any other ideas?

i've always gotten a test light for paracidic draw and unhooked the battery, hooked up the test light (i think i had the clip on the unhooked positive side and then used the battery for ground) and if the test light comes on then there is some type of paracidic draw. after that i'd just go and pull one fuse at a time until the light stopped and then you know whatever is on that fuse is what is causing the draw.

Geekstarrs test is a good one, although I like to use a multimeter set on milliamp scale, instead of a test light. Then pull fuses until you find the right circuit with the draw.

I think you'll find a constant 6 mA draw, that is constant no matter what you disconnect (although 30 mA is indeed excessive). It's caused from the ECU being powered with the key off. It's not enough to be concerned with, unless the XJ sits for an extended period.

If you have a courtesy light above the passenger side visor, make sure it's actually turning off. Also underhood light, if you have one.....a 30 mA draw is about right for a small bulb being on somewhere.....

Testing with a test light/DMM and pulling fuses is a good troubleshooting method to determine which circuit the draw is coming from. It doesn't work in all cases, though.

My power drain issue took a very long time to diagnose, even stumping several shops, and I found it by accident. It was caused by the power antenna. I heard a faint click sound about every 25 seconds coming from the passenger side front fender where the power antenna is located. I just raised the antenna and then clipped the three wires. My problem solved.

It was a total PITA but was very happy when I finally fixed it. I hope you find the cause of your problem soon. Please post up when that happens.

OK, I must say that I haven't been posting my trials and errors as much as maybe should have been...

I did run all the 'fuse pulling party' test with both a test light and and multimeter without success all 4 times I did it (twice with each tool). Unplugging the alt overnight didn't do anything either.

the other night my amp stopped working mysteriously...I checked the power at the amp, and was not getting a complete circuit. I decided to pull the power wire for the amp out of the car to verify that it wasn'y chaffed or scrapde somewhere. Nothing found. I tested the wire before re-installing it to make sure it was working correctly then proceeded to completely re-run my power wire and re-gound the ground wire. This time I KNOW it was done well. Amp didn't work. Turned out to be the inline fuze...it's a nice phoenix gold barrel style fuse, that showed no sign of it being blown. I even tested the continuity and resistance of the fuse having the results turn up more/less perfect. But while installed, it didn't work. I replaced the fuse, boom booms are back in action!.

At this point I felt confident that the problem was somehow mysteriously solved. It ran all day yesterday without a singe problem with it draining amongst running various errands throughout the day.

Upon heading out for some Chili's last night... :shocked: !! The battery had been drained out like before! AARRGG!!! BEing that it's now warm outside my GF went to roll down the passenger window, and it didn't work! but it WOULD work from my driver door (no, the window lock wasn't on). Once I got home, I messed with the driver door switch cluster...maybe something is shorted in the switch...when I wiggled it the button lights on the other 3 doors would come on/off. I left the switch cluster unplugged overnigth hoping to have a good battery in the morn.

NOPE!!! :smsoap:

So as I am dissapointedly removing the door panel to put the switch cluster back in, I remembered that recently that my driver door speaker would cut out occasionally when I opened the door, and thought it was time to check all the wiring in the door for anything not good. At first, I found some of the electrical tape near where the two harnesses come out of the door for the windows/locks/mirrors had been scrped up a little, but the wiring was OK. This prolly wouldn't explain the speaker problem, but was notable. I then continued down to where all the wiring was between the door and the car...wiggling this boot made my cpeaker come on/off.

So after pulling all the wirnig out, so I could look at the wiring, I found this:



After cleaning all this up with elec tape, and reassembling all, I feel a little better about what the problem may have been, time wilk tell.....

I think the reasons why the 'fuse pulling party' tests didn't produce anything and why this was intermittent from time to time was because opening and closing of the door may have made these wires short sometimes and sometimes not.

Hopefully this is the end of it as we are heading out for a 3 day camping/wheeling adventure this wekend, would hate to be stuck somewhere in the Rockies with a dead batt!

Wow, that's a bad case of broken insulation; hope that was the cause of the battery drain. Thanks for posting back.

Have a good holiday and trip.

OK, well....

Unfortunately, my problem still isn't solved. The battery is still draining for some unknown reason. And did so over our trip on Memorial Day weekend.

Last friday night, I put the battery on a charger and let it charge up overnight and pulled the charger off Saturday morning. It worked out that I didn't drive the it until Monday. When I went to start it, expecting the now 'normal' slow start, it fired up like nothing, and has the last few times I've started it, even today (tues). I guess I'm going have to keep hunting down similar areas that may have the same thing happened to them. It definitely appears that something is getting shaken around or moved while driving amd causing this intermittent problem.

If anyone has any suggestions or now if there is any common areas this may occur it would be a great help.

Thanks to all that have put in their info thus far.

I had a similar problem with my '88 XJ. Killed the battery while camping in the Canadian "out back". Problem was a chafed wire going to the under-hood light. Every time the hood was closed, the wire rubbed against the holder for the coolant bottle mounted on the fire wall. I cut out the chafe, added more wire using barrel connectors (field repair!).

I know this is an old thread, but I *did* do a search as recommended

I have had a similar problem for months. Last night I discovered that corrosion from the positive terminal had bridged the gap between the battery terminal, and the hold down clamp. It conducts just enough to drain the battery in a few days of no driving. I suspect I will need a new battery now, since batteries don't like to stay discharged for a long time.

XJ16..good point...they call that surface voltage...the leakage down the battery across the positive and negative due to dirt on top of the battery. Part of all services should alway include cleaning off the top of the battery.
I clean it with a little windex every time i see dirt on the battery.