Tuesday I take my XJR to my mechanic for a oil change and tire rotation. I basically use these guys for oil changes and nothing major. Drove home about 9:30 and parked the car in the garage. Yesterday (Wednesday) afternoon I decide I want to evaluate what O2 sensors I want to do first, open the door to pop the hood and no interior lights. Then I hear some rapid fire clicking..... huh ? I click the key a few times and doesn't lock or unlock as its got nothing. The clicking is coming from the trunk so I open is and the fuse box is what's clicking like a time bomb. I removed the battery cable, it stopped, waiting like 15 minutes just touched it again and the rapid fire clicking started again which I figured would happen since the battery is dead. I put a new battery in this car no more than 18 months ago. Even though I'm in AZ where they run down quick I don't think its that.

Thoughts ? I will charge the battery and I'm pretty sure with a full charge it will start but I'm stumped. I know its early in my quest to figure it out but anyone else have this rapid fire clicking from the fuse box. 13 Jags in my life and I have heard this before.

Thanks in advance.

 

The clicking sounds like one of the relays constantly switching.
The rear fuse box contains 4 conventional plug in relays and another 4 relays that are part of the printed circuit board.
You could pull each of the 4 plug in relays in turn to see if the clicking stops to identify if the clicking is coming from one of these.