So yesterday I'm driving around town in about a foot of slush & water (no joke) but taking it pretty easy. I get to a store, my wife jumps out and I look down and see the "Check Gauges" light on. Battery is completely gone, i.e., not even registering. I have a brand new battery as of a month ago, haven't left anything on, etc., and then I notice all the interior lights are on. Hmmm, that's weird. Pop the hood, jump out in the pouring rain and have a look. Nothing looks weird, everything is KINDA wet but not ridiculous. Jump back in and start thinking about what it could be. Wife comes out, tell her what's going on as I run her (my XJ) back home. Get home and shut her off, lights are still on and it looks like smoke or steam pouring out of the hood. Not good. Pop it again and have a look and it appears to be coming from the alternator area. I have keyless entry and try locking/unlocking/locking the doors over and over. Interior lights refuse to turn off. So, I unhook the battery.


My alternator is about a year and a half old. I'm wondering if maybe some water splashed up in her and shorted something?


Anyone have any ideas?

 

Pretty good chance the alternator is not happy. Start it up and test voltage at the battery with it running.

Should be 13-14 volts.

If its any less than that you should replace the alternator. Wait until it all dries out before you test it.

 

Batt gauge completely dead but still power/int lights? Agree with doing some checking first.
Check batt voltage with key off and then with engine idle, should be at least 0.5V above key-off voltage (which needs to be at least 12.4V, preferable higher).
Then, with engine running, turn on as many accessories as possible (except your rear windown defog), rev engine to about 2000 rpm's and see if your voltage/charge holds up.
If not, dont condemn your alternator just yet...

 

Did the interior light dimmer control get moved to always on?

 

djb383, it did not. And the power windows would NOT work either. Forgot to mention that.


So yesterday afternoon it stopped raining and the sun came out for a little bit, along with some wind. I popped the hood for a few hours hoping to dry things out a little more.


I connected the battery and looked inside, no lights on. 1st good sign. Put the key in and turned on the power, the battery gauge went right up. "Well, lets see" I thought, so I turned her over. It sounded a little odd but she did start and run.


I cant find my multimeter, so Im guessing I loaned it to someone and they never returned it. A new ones on my Christmas list. In the meantime Ill just keep an eye on things. Guessing too much water got in somewhere.