Benjamin Breeg

Monday afternoon, my girlfriend drives her 97 home and leaves the lights on, totally killing the battery. It wouldn't even turn the dome lights on Tuesday morning. We tried to jump it with my 96 XJ, and at first all we got was power to the lights, radio, windows etc. and a clicking noise when trying to start it. Not the usual single *click* but a series of clicks in quick succession. After a few more minutes with the cable attached and mine still running, hers would crank but not start, and a few more minutes later hers fired up. I drove it around the block a few times, brought it home and turned it off. Started up again just fine. Went for a longer drive later to give it more of a chance to charge and had no problems. Wednesday morning it started fine and she drove it to work. After sitting in the parking lot at her workplace for about 6 hours it again wouldn't start. This time, the lights, radio, etc. still worked and there was the normal, single *click* when trying to start it. Instead of jumping it, I swapped the battery in hers with mine and it started no problem. Thinking the battery had gone bad, we drove hers home and let mine sit until we could get a replacement for the bad battery. On the way home we stopped to get the charging system tested just to make sure that wasn't the problem. No issues there.

The bad battery being a Bosch, I took it to Pepboys and had them test it. They told me it was good and at 100% charge. My plan now is to leave the battery that was in mine but is now in hers in hers, and try the suspected bad Bosch battery in mine.

I was wondering if anyone has any ideas as to what else may be causing this problem. Thanks!

HS00XJ

Inspect batery cables and grounds

Radi

^^ +1

Clean, shiny and tight with no corrosion inside the cable jacket?

srocks

If its an automatic, the neutral safety switch (NSS) is worn. I had similar issues with my 94' XJ automatic. I discovered that when I jiggled the gear shifter when its in park and turn the key at the same time, it would start up most of the time. After this trick stopped working. The jeep wouldn't start up at all until the NSS was replace. Since the replacement, never had any issues starting up my jeep.

Search this forum for the NSS and/or google. Good luck.

Radi

If the NSS is bad there's generally no 'click' when the key is turned to start.

salad

NSS causes bad batteries? Hm that's a new one...

Did Pepboys do a load test? Batteries in cars are NOT deep cycles. If it was drained to the point that you didn't even have any lights in the cab, that sucker is probably done for. Discharging that far actually causes permanent physical damage.

Relays from the junction block maybe

PocketsEmpty

Are you sure she didn't leave the lights on again?

Benjamin Breeg

That was the first thing I asked hahaha!

We've had the battery from mine in hers since yesterday afternoon and everything's been peachy. This morning I put her battery in my jeep and it fired right up. I did a lot of cleaning of connections and terminals today so we'll see if the gremlin returns or not...

Radi

The Start relay is grounded through the NSS, it won't activate if the NSS is bad.
There may be some other relays that chatter in the "ON" position.

salad

Any relay that's powered in RUN but not START should shut off. It's a small click but noticeable, at least in the middle of nowhere at 1 AM it is! When my clutch interlock failed I heard I thought there was some other sort of problem, as I could still hear "clicking" when turning the key (never had a no crank prior, yes I'm just a young'un). Clutch interlock sits between the ignition switch and the first starting relay in the JB.

Radi

Good point, I hadn't considered that.


Wait 'till you get a bit older, you'll stop hearing that stuff too.