This is strange. When I power on the radio, the retractable antenna goes up, gets to the top then the fuse blows while, at the same time as the fuse blowing, the passenger door puddle light comes on and stays on even after the fuse is blown. Antennna stays up. When I turn the radio off, the puddle light stays on and antenna stays up. I then turn the car off, replace the fuse and the antenna retracts and puddle light goes off. Fuse stays unblown until the antenna is powered up again and the whole thing repeats.

I initially thought that the fuse blowing may be the result of too high draw by the antennna motor, but then why would that puddle light come on? And then stay on even though the fuse is blown.

Odd......

Any ideas?

 

I looked at the wiring diagrams. On my car Fuse 17 feeds the front door puddle lights? The feed to the left light is in front of a diode the right side is behind the diode. These lights are normally not on because the circuit goes to ground when the door is open. Begs question as to why the circuit goes to ground on the right side when radio antenna powers on thereby bypassing the door switch.

I have a theory that the antenna fuse blows at the top of the antenna travel leaving the antenna motor switch in the "move up" position which provides a path to ground through the antenna motor even though the fuse is blown. This would allow the light to come on without the switch.

The Wiring diagrams are 11.1 and 14.2 respectively. Anyone with electrical expertise want to weigh in on whether this theory is plausible?

 

The antenna fuse/puddle light problem was documented in a Jaguar TSB (Technical Service Bulletin) and described merely as a 'backfeed'.

The bulletin describes adding a diode to the puddle lamp circuit and mentions that later cars would have the diode installed during production. I can't remember any details at the moment.

As mentioned the S57 Guide shows a diode. I've never been clear if that diode is the same one mentioned in the TSB .....which means that some cars wouldn't have it unless retrofitted.

Or maybe all cars had the diode as shown in the S57 and the bulletin refers to adding an additional diode?

In any case, the problem is known, not unique, and fixable. Of course fixing the antenna problem is one way to go about it!

Cheers
DD