About a year ago, my Jag developed an intermittent, minor issue with the alarm, in that, occasionally whenever I'd lock the car with the fob, there would follow an individual high pitched "chirp" as though something wasn't properly closed, although all the doors and boot would lock.

This issue disappeared all by itself so, I left well enough alone.

Another minor glitch was the fact that the rear passenger side driving light would sometimes only "half" illuminate, that is, only one bulb would light. The lamp failure warning would illuminate on the dash warning and by giving the offending lens a gentle tap, the light would come on. I checked all the wiring/connector, wiggled everything and even swapped the fitting from my donor car, but still no change. Then this issue also resolved itself.

Until this week! I needed a battery for another car and so I got a new one for the Jag (bigger at 100ah than the previous one which was 88ah) and swapped out the old Jag battery to my project car and since then, these two intermittent issues have arisen again.

For what it's worth, the battery sits on the opposite side to the intermittent rear lamp and was fully charged when fitted a few days ago.

I'm not losing any sleep over this, just bemused and perplexed! Who knows........

 

I would say corrosion in the wiring or a short maybe even bad fuses but that doesn't seem as possible but the door locking mechanism and or the fuse to it may have gone bad.

 

I get the second chirp once or twice a month...but it is always true....for whatever reason only the driver's door will lock, then you get the second chirp, I hit "lock" again on the FOB and the other doors lock and all is well.

Sometimes, when I go out after work the FOB won't unlock anything, so I use key in driver's door. After one key-opening, FOB functionality almost always returns...on rare occasions you will have to lock/unlock with the key maybe once or twice more. I just figured it's part of the car's mistyque.....