I went to take my Jag out today for the first time since last Fall. The battery was dead. I opened the hood, and put the charger on the leads in the front, and let it run for about 30 minutes. After that it started, and I took it to the market and back.

On the way home, I tried to open the top. I pushed the button down, and nothing. Pulled it up, just in case I didn't remember the correct direction to open the roof. Still nothing.

It is in the garage now, and back on the charger, since the red triangle was on in my dash - so that it can get a full charge.

Is there some special ritual, incantation, rain dance etc required to get the roof open after a battery re-charge?

Thanks.

 

The very first thing to do is to disconect the negative battery lead on the trunk floor. The illuminated red triangle (assuming it has been lit for more than 15 minutes or so) means that there is a drain on the battery...and it is likely from having an OBDII reader used before the car was put away for the winter. Disconnecting the battery for 30 seconds will reset the system; it can then be reconnected and charged (assuming that it will accept charging to full voltage).
You have no problem with the roof. That is a red herring; you have a depleted and possibly damaged battery from being allowed to go completely flat.
You must deal with the battery situation before trying to lower the roof...I assume that you do not use a CTEK battery maintainer during the winter?

 

Always carry a small adjustable wrench with you in a cubby hole - If you experience ANY electrical 'funnies', whip off the +ve battery terminal for a few seconds, and then re-connect - et voila!
And, yes, it's perfectly safe to remove the +ve as opposed to the -ve, as there is no nearby metalwork to 'short' your small wrench to...and it's easy to reach.

If that doesn't work, carry around $2000 in your pocket!

 

I see! lol, no I've never owned a car this nice. Every other vehicle I've owned you could park for a few months, and the most it would need is a little recharge. This one is "beyond"! Other than my Harley, I suppose.

LOL, but seriously, I really like the car...

I'll get a tender for it.

 

It's a British sports car in loose 'ish terms.

You'll get used to tending to it and carrying an adjustable. Part of the fun of ownership!

 

...done deal! Disconnect/reconnect after some more time on the charger, and the top comes down. Also got the CTEK 7002, and hooked the little dongle to the battery in the trunk, and plugged that in, so it'll be on maintain as long as it is parked.

...an 11mm socket was lost in the war. Slipped down under the battery tray, and I didn't feel like unbolting all of the electronics off the trunk bottom to get at it. Will just go buy a new one, and will deal with it if it turns out to be noisy rolling around back there.

 

Well done. As you see, it is almost always the battery, even when you think you have a major malfunction. I wonder how many instances like this contribute to the low quality-ratings? Complaints about the electronics in modern cars form a major part of the defects or so-called defects.

just one thing:the CTEK unit should not be connected directly to the battery in your car. The positive CTEK lead should be connected to the unit beside the battery (black box, multiple connections inside to one bar, connect to any pint on that bar); the negative lead goes to the ground point on the trunk floor, where the battery negative. Lead is connected.

 

Ah yes, the box. What does connecting there do differently from connecting straight to the battery?

 

If you connect directly to the battery you bypass the car's battery management system. Jaguar's instructions regarding charging on cars with the battery management system clearly set out the procedure. It is just as easy as connecting directly to the battery but you will not mess up the system and lead to further problems.
The CTEK can be left connected indefinitely and will avoid any problem such as you have encountered....assuming, that is, that your battery has not been damaged by the deep discharge (meaning that its life may have been shortened substantially. You do not know how long the battery was left fully discharged, correct? And you have set the CTEK unit to the AGM charging cycle?

 

The BMS module monitors the NEGATIVE and is connected on the battery -ve post. It is in series circuit electrically.

The +ve batt post is at the same potential as the busbar both physically and electrically, so connecting here or the post is fine.

What is important, is that you connect -ve of the tender to the car chassis/body.
This is so current and voltage is measured by the BMS before it reaches the -ve post.

JLR recommended practice is to connect +ve to the busbar with all the fuses...it makes no odds.

You could connect the tender straight across the battery terminals or even to the under bonnet connections. For low current feeds they are all at the same potential.

Anything metal floating about under the battery tray like your 11mm socket is asking for trouble...Murphy's first law states that it will fall against something it shouldn't when you're least expecting it!

Magnet on a string is the other essential special tool as well as the small adjustable wrench.
The magnet helps retrieve tools dropped from the engine area into to plastic underway...and from the hinge area of the drink holder!

 

I have a magnet, and tried that.. It just stuck to all the other metal under there. Oerhaps driving real fast in a left-hand circle would make it roll out...

Otherwise maybe I'll resign myself to spending a couple hours disconnecting and removing the battery entirely, to get at it.

Also discovered the bus bar being electronically equivalent to the + post when I went back and looked at it, so I left it.

Negative side is bolted to one of the battery tie-downs..

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... lol, if you saw my garage, you'd know I've got a magnetic retriever among other things. I have a lot of "tool" hobbies.