After-Market Radios & Antennas

It appears Superblack’s PO had replaced her stock '92 Alpine radio w. a modern JVC (KDR series, circa 370 or so) radio/c.d. player. I don’t care for the quality of the sound, as the Alpines had a better one, IMHO, with more “power” … :-1:

Anyway, I guess she’ll do for now, but someday I would hope to find another stock radio to put back in her (assuming I decide to hang onto Superblack). One thing I don’t like about the JVC is that the power antenna no longer does its thing – only stuck permanently like 1/2" above the surround. No sound of the motor coming on or off when the radio is turned on/off, either. I’m thinking this is b/c the power antenna system is not compatible with a modern radio, like the JVC model, so it was not hooked up (or couldn’t be hooked up) after the r/r. :thinking: Am I correct on this? Is there some way to get the antenna working with it? I always thought the powered antenna was one of the coolest features of the XJS (or any vintage Jag). :cool:

Have spare radio…don’t. know. If it works…you are probably better off with aftermarket

The radios usually have some accessories connection. Powered when on. This runs the antenna in my XJ, and it’s a low end late 90‘s BMW unit

Probably incorrect. No changes in the way power antennas are activated in the last 30 yrs. Every aftermkt deck I have installed (100 or so) has the “power antenna” or “amp turn on” wire. Deck on=12v=antenna up. Deck off =0v =antenna down. Check at antenna to see if you are getting 12v. If yes, antenna problem. If no, Do your basic tshooting working backwards from antenna thru relay to deck and determine where you are not getting 12v. As usual, I think the Book has good descriptions of the various power antenna afflictions from which the xjs may suffer.


Ionically, I did an aftermarket power antenna on my Bentley Turbo R today. Most have 3 wires:

1.contant power (red)
2. power from radio (yellow or blue)
3. ground (black)

Unplug the wiring to the antenna. Get a test light to check the wires for constant power (with radio off) and one wire with power when radio is turned on.

Most if not all aftermarket antennas will work. It’s the mounting that can be frustrating!



The radio/ antennae circuits aren’t the same for all XJS cars.

I replaced the original (dead) radio in my 1984 XJSC 3.6 with a later
1990 version & the power antennae wouldn’t work. I found the antennae
up/down signal wasn’t powerful enough. I fitted a power transistor to
increase the current & it has worked since, this must be more than 10
years ago. The antennae may be an after market replacement.

Best regards

Brighton UK

Thanks (all) … will try those ideas … I too wondered if maybe it was possibly bad “up” and “down” relays or blown motor unit. Testing for electrical power though would be the sensible first approach. :smile:

I believe the Hirschmann antenna in the XJ-S fits this same scheme. However, there are two factors I know of:

  1. My ‘83, a plain ol’ XJ-S coupe, had a delay module in the line. I was never too sure how it was supposed to work (my antenna didn’t work when I got it) but I think the antenna was supposed to go up the instant the radio was turned on but would wait something like 15 seconds after the radio was turned off before going down. Reason? Unknown. I replaced my dead OEM antenna with a cheapo aftermarket power antenna and ditched the delay unit altogether.

  2. The models that had rear deck spoilers, XJR-S’s or whatever, had the antenna wired into the trunk lid somehow so that popping the trunk open caused the antenna to retract.

As to #1, yes, there is that delay … Have it with Superblue’s, had it with Supercat’s back when I had her ('95 coupe) and even had it with my XJ40s (and I believe when I had my X-300). The delay was supposed to allow the driver to get out and clean their mast (i.e. swipe upward once with an alcohol wipe), if desired, before it started to retract. I know that sounds kinda, dumb, in that if you just keep the radio on it will stay extended, but you know how Jag had a thing for “convenience” features. :roll_eyes:

No, it’s purpose is that when you start the car and you have the radio on, the mast doesn’t start to go up and down every time you hit the starter.

Yes, that was my guess. But it begs the question of why would you need to keep hitting the starter? I suppose the recent threads on stalling and hot restarts is part of that. I would have liked to see some more work going into those issues, rather than a time delay bodge on the aerial.

Supplemental question: how many time delay bodges are there in an XJS? Probably the US market has the most, given their obsession with startup emissions control.

My 95 coupe is stock unit, no spoiler to contend with, and IIRC has no noticeable delay either side of on-off of radio. I got in the habit of switching off the radio and A/C when getting ready to turn off the car.
I heard one time that the delay on shut down was eliminated due to folks opening the boot before antenna was retracted and catching/bending within the spoiler. Don’t know if that is true.

Erm… have ya repaired the rusted-off trailing arms, yet?


That is certainly the case for the TWR and XJR-S cars that have a boot spoiler. The antenna circuit is connected to the boot lid switch so that it will retract as soon as you open the boot. The early cars had the antenna going through a hole in the spoiler (lots of scope for entanglement there). On later cars it was just on the wrong side of the spoiler, but still a problem.

Hehe. Dumbest XJS thing I ever did was buy $159 floor mats for one my ‘92s in the assumption I’d figure out why it won’t run very quickly. It’s been two years.

I guess it serves that purpose, too, but I know I had read the “clean the mast” reason given on here before some time back … :thinking:

Still waiting on them (the repair piece) from the U.K. The past 7 days the Royal Post tracker says it is “processing at Langley”, whatever that means. I have asked the vendor if that is some sort of customs stations there in the U.K. before it leaves the country. Waiting to hear back from them. :crossed_fingers: In the meantime, the partner USPS tracker shows another full two weeks before delivery. Ugh! :frowning:

I thought I read in a manual somewhere that on the 6.0s w. the spoiler there is some 'safety feature" that if you unlatch the boot lid while the antenna is extended it immediately begins to retract. :question: Isn’t there also a clearance hole in the spoiler for it?

John, do you happen to have a copy of the Driver’s Handbook for the '92 MY? I’m still looking and needing to buy one, but still the only ads I have seen out there is that dude on Ebay who is asking $600 for his. :crazy_face: Hell, I’d pay someone $100 just to photocopy theirs for me. :pray:


Either way, I have no spoiler.