I know what most will tell me, replace the battery, but just want to talk about this....

03 XK8 with no problems other than this irritating little issue.

Battery is dated 9-11 so right at 4 years old. Other than that being a jinked date code, 911, it appears to be in good condition. I run a Scanguage and after start the voltage reads 14.2/3 for awhile then settles down to 13.6/8 while driving. I understand this is the regulator output voltage not the battery voltage.

After sitting for 24 hours the battery reads with a VOM at the terminals 12.4.

I have a remote top mod from WhiteXKR, has been on the car for about a year.

Now the issue.....
About every third time I try to put the top up using the remote it malfunctions. The only symptom is the drivers window only raises about 2 inches, drops 1/4 inch, top goes up, all other windows go up correctly, drivers window goes back up the 1/4 inch. So everything works except the drivers window appears to forget it's location for proper operation. When it does this I reset the drivers window and all is well for another few cycles.

Last night, we went out to dinner, used the top remote down and up, no issues.

Made a few stops, bar hopping with friends and no I was not drinking as the DD, as it was a beautiful night on Maui we were dropping the top every time. Well after about the third stop when we came out and the remote would not drop the top, period, no indication of the command even being received. Top worked correctly with the console switch. This was new as it normally malfunctions on the up cycle! Next stop same thing, put top up OK with the remote but it would not drop using the remote when we came back out. Remote appears to work as the lights came on as normal and the car unlocked.

Now for another twist...

We were waiting in a parking lot for a friend to catch up with us....sitting in the car, top down with the parking lights and radio on, car not running. After about 10 minutes, started the car and moved about a block to another parking space at the next watering hole. I normally have my lights on auto and never fool with the switch but as we were sitting above I had switched the lights to have the parking lights on and forgot about it. When we got out the top went up correctly using the remote however as I was walking away I noticed my lights were still on. I had forgotten I had switched them to parking lights, so I went back to the car and the remote would not unlock the car. I had to use the key in the door to unlock and turn the lights off.

Came back out an hour later and the remote worked but would not drop the top.

When we got home the top went up correctly using the remote. This morning I went out and metered the battery and got the above 12.4 reading. Without starting the car the top cycled correctly down and up using the remote.

So long story but any ideas on what is causing this?

 

I suggest as a starting point to remove the door panel and inspect the wires for the remote top and the door module for any physical damage.

I have seen them get caught up either between the window and the window track, or in the door check mechanism between the hinges. This can tear the wires, or intermittently short them together or to ground, causing a variety of intermittent issues similar to this.

If this is the case, the simple solution is to repair any damages wires, and then use wire ties to keep them out of the way of moving parts.

 

Thanks Steve, I'm on vacation next week just working around the house and have some maintenance planed on the Jag, oil, trans fluid change, fix parking brake and head rests, few other minor items so will put this on the list to check. I do have the wires zip tied inside the door but I've always worried about the window catching them so will inspect and re-secure.

Guess I'm just spoiled as I like the top remote and feel irritated when I have to use the console button!

Funny, I'll spend money on things I want but don't "need" for the car but spending $200 on a new battery makes me think twice. Go figure...guess I don't see the battery as the cause as it appears to be in good shape.

 

4 year old battery is not so young and the demand the components of the car put out, MAYBE it is a battery issue. This one is on the fence.