Hi,
No radio in my 1990, XJS coupe since I bought it a few months ago so splashed out and had one installed today. The radio is fine but the electric aerial refuses to budge. There is power getting to it and the relay can be heard to click so I'm guessing there is something wrong inside (?).


The aerial is supposed to be a new unit fitted 5 or so years ago but may not have been used since. Do these seize up through lack of use? Any thoughts as to what else it may be / things to try before I splash out and buy a new one?


Thanks,
LeeP

 

I can suggest the following things to try: In the boot just on top of the exhaust tunnel behind the ECU on the US passenger side, is a green relay. This controls the aerial and provides a delay on its retraction of about 15 seconds or so. This relay has to be earthed for the aerial to work. There should be a black wire coming from it to earth, which can easily be forgotten or not properly earthed.


The relay should have a permanent 12v feed with the ignition key in its first position. Test that the permanent 12v feed is present. Then, when the radio is switched on, you should find (a) the signal current coming to the relay down the white/red stripe wire from the radio, and (b) current coming into one of the aerial feed wires from the relay. If not the relay may be faulty. When the radio is switched off, after the delay period, the OTHER wire to the aerial from the relay should go live.


To test the aerial, hotwire 12v + and - directly to the two aerial wires, try one wire + and one wire - or the other way round, to make it go up. Reverse the wires to make it go down. If it does not the aerial motor is faulty.


If the aerial is Ok, and the relay is receiving current and radio signal, it is the relay.


Greg

 

On my 86 I took the assembly apart, cleaned and lubed and it works well now.

 

My relay is removed / a simple toggle switch (and wiring run from the boot of course) hidden under my seat / carpet is the replacement. Something to consider to omit possible battery drains and car wash deaths.

Jeff

 

Thanks chaps for all the suggestions.


I tried bypassing the relay and feeding power direct to the aerial but no go so it is presumably dead. Also checked the car's history and although it had a replacement mast in 2005 the aerial motor, with its Jag emblem, is presumably the 25 year old original so time for a replacement.


Bought a genuine Hirschman replacement from a specialist supplier and will let you know how I get on.


Jeff - like the idea of a bypass switch, I may try that anyway.


Cheers,
LeeP

 

The genuine Hirschmann replacement that I bought from an aerial specialist was a straight swap and easy fit. Also a little cheaper than the normal jag suppliers.


Very satisfying watching it go all the way up for the first time in many years! However, the 10 second delay before it folds back down had me worried - 10 seconds seems a long time when you think you have messed up the wiring.


Cheers,


LeeP

 

10 Seconds delay is quite normal, glad its working Ok.