I posted recently about radio reception problems on my 2008 XKR:
https://www.jaguarforums.com/forum/x...eption-293805/

But starting a new post since that one has good information on the shark fin versus spoiler antenna.

My AM/FM reception started being bad all of a sudden. I had noted that if I disconnected the coax feed going into the AM/FM amplifier in the boot and attached an external antenna to the feed, the reception became great. So my assumption was that it was the AM/FM amplifier, wiring between the antenna amplifier, or the antenna that was bad.

I grabbed an AM/FM amplifier from a junkyard and swapped it, and still had a lack of reception. I disconnected the coax going into the spoiler antenna and connected an external antenna to the feed side, and still had a lack of reception. So that seems to have eliminated both the AM/FM amplifier and antenna?

So I then tried connecting a jumper wire from the AM/FM amplifier plate to the ground wire post behind the right rear tail-light which feeds into the tailgate harness, and I believe is directly connected to the glass heater since the glass wouldn't be grounded at the tailgate. With that jumper, I had great reception, but I then tried attaching the jumper from the AM/FM amplifier plate to the glass heater connector and didn't get a reception improvement, so it's almost like the ground wire was acting as an antenna when I ran into directly in the air to the ground post behind the tail-light. If it's worth noting, I did check and verify continuity between the base plate of the AM/FM amplifier and the ground strap on the boot hinge.

I'm now pulling my hair out trying to diagnose this and wondering if anyone has any suggestions or common failure points I may have missed. I'm not clear where the AM/FM splitter is located either. Any help would be greatly appreciated!

 

“My AM/FM reception started being bad all of a sudden. I had noted that if I disconnected the coax feed going into the AM/FM amplifier in the boot and attached an external antenna to the feed, the reception became great. So my assumption was that it was the AM/FM amplifier, wiring between the antenna amplifier, or the antenna that was bad.”

Do you really mean the coax ‘coming out’ of the amplifier, instead of ‘going into’? Otherwise your attempt with another amp doesn’t make sense.

Maybe the junkyard amp is junk also?

 

My understanding is the feed goes from the radio, to the AM/FM splitter, to the connection behind the right rear taillight, to the amplifier in the boot, to the antenna in the spoiler. The amplifier is only needed because of the small antenna hidden in the spoiler, meaning if it had an old school 3 foot vertical antenna, it wouldn't need an amplifier.

So I took the amplifier and antenna in the spoiler out of the equation entirely, and connected the coax going into the amplifier with an external 3 foot antenna, and that's when I had great reception. Does that make sense now?

It's certainly possible the junkyard amp is also junk, but makes me at least second guess what might be going on.

 

Ok, you’ve clarified your scenario, thanks.
But let me point out that the ‘feed’ is in the reverse direction. The antenna is ‘feeding’ the receiving radio. (The radio station transmitter ‘feeds’ its transmit antenna. Feed is in the direction of the energy flow.)

 

Ah yes, I see what you mean.

 

On the amplifier side, it would be great if someone could look under their tailgate to help clear up some confusion.

The electric manual shows there should be 3 connectors going into the AM/FM amplifier: TA012 (power), TA013 (module signal splitter), and TA014 (antenna). I only see power and what I believe goes to the signal splitter. Does anyone else have three?

Separately, I found the tech bulletin for upgrading a 2007 XKR to use the 2008 version of the antenna in the spoiler, and it indicates a dedicated ground wire is used for the amplifier. I certainly don't have one, though I do see GA50AS ground point in the connector reference which looks like it comes out of the same tailgate harness?