Whats up guys. So i recently started using my 2014 XJ AWD 6 again after having it parked up for almost 2 months without starting due to a broken plastic tube that was causing a major antifreeze leak and preventing the car from being driven. The supercharger had to be removed to get to that damn pipe, what a dumb design. None the less, now when i drive the car at times my headlights and all of the lights in the car flash like it was loosing ground or power all together. I get all of these warnings for a quick second in the instrument panel and then the car drives fine. Anyone have any ideas?

 

Don't know the thread, but someone had a similar problem and it turned out to be the light switch on the column.

 

It could be just a coincidence that you had major work done and now it's messing up, I would suspect something was missed on reassembly though. I took my Corvette in once and on the test drive afterward I found antifreeze all over the engine, They had left a hose loose and it leaked all over, It was in the way for the mechanic and he accidentally left it loose. That didn't bother me though, it was his instant denial that it couldn't be anything he did. I got a call at closing time saying it was ready. I went down there and only some 18 year old kid was there and he told me the mechanic found it loose but they weren't going to charge me for fixing it. I told him okay, thanks, but I never went back. If a Doctor makes up something instead of telling me "I don't know", I never go back to them either.

 

etaent, from the sounds of things, you have either a bad power wire feeding the power box in the passenger compartment or the ground wire between the passenger cabin and the engine block is bad. You can try adding say a 14 gauge wire between a bolt on the body and the engine block (make sure to leave some extra room, 3-4 inches, to allow the engine to flex). This will tell you if it is a bad ground wire. If the problem continues, then you are most likely looking at a bad positive wire. Based on the work that was recently done on the car, I would be looking at the plugs on the firewall for one that isn't seated all the way and also where the power comes off of the alternator and splits.

 

Thanks fellas, I will check all of that. Out of curiosity, I have read that the small accessory battery in the trunk could also be to blame and may need to be replaced or charged. Any thoughts?

 

The little battery is for the stop/start function. Not used for anything else.
.
.
.

 

Agreed, my smaller battery failed well before the large one needed replacement and in neither case did I have electronic issues.

 

I had the smaller battery checked and as it turns out it needs to be replaced. I ordered a replacement and will update everyone once I put it in. I checked all wires and connectors and everything is 100%. So I am going to make sure all the simple stuff is corrected before I dive in any further.

 

Hey etaent, I am having the same problem with my 2012 XJL Supercharged. It will drive, but the entire power to the car will cut out from two to four times in a matter of seconds, then I'm left with a blinking warning light for my adaptive headlights. It happened at night a couple days ago and losing my headlights even for a split second was spooky. My stereo speakers also click one at a time very quietly and the audio pulses on and off. Even when I don't completely lose all power, I have slight power pulsing like the car wants to lose power, but not all the way. Then it will drive perfectly fine for three or four days and make me forget about it. It's happening more often now, and I need to figure this out.

Have you gotten any further researching what's going on with your car? Or has anyone else experienced clicking speakers, cutting audio, power pulsing, and complete power drops?

Thanks!

 

You should probably start your own thread and tell us what the voltage does when this happens.

 

I am not sure if the 2012 has Eco drive with the start\stop functionality but if it does then I would disconnect the small auxiliary battery in the trunk to see if that resolves the problem. I did on mine and have never had that problem again. I am currently trying to source a replacement battery as its a $50 battery in Europe but here in the states the only place I have been able to find it at is at the dealer where they're asking a cool $290! Let me know how it goes for ya!

 

There was no stop/start prior to the my2013 so that cannot be your issue. IMHO it's either the battery of one of the main + or - cables.