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Aerial

finchleyman
Posts: 13
Joined: Mon Oct 31, 2011 12:13 pm

Aerial

Postby finchleyman » Tue Apr 07, 2015 9:34 am

Hi - the aerial no longer works, refuses to raise, it could be the motor I guess, but I wondered if it may be a fuse? Being completely ignorant of these things, could someone identify where the fuse is that covers this area? Many thanks!
Tony B
Finchley, London
1995 Jaguar XJ6 X300
2007 Mazda 3

M-e-l-l-o-w
Posts: 1431
Joined: Tue Jun 29, 2010 4:20 pm

Re: Aerial

Postby M-e-l-l-o-w » Tue Apr 07, 2015 3:07 pm

If it is the same as on the late 93/94 XJ40’s I think you will find that the aerial mast has some in-built electronics that sense the motor power used.

Basically I think the head unit sends a coded pulse to the aerial that then powers the motor to raise the mast until the power needed starts to go up dramatically as the mast reaches its full extant and it then cuts the power to the motor.

When the head unit is turned off either via the on/off switch or via the ignition key the head unit then sends another coded pulse to the aerial that does the same thing but with the motor running the other way.

At the aerial you should have an earth wire (black) a 12v power wire (brown with a blue stripe) that is always live and the thin control pulse wire (light green with a black stripe) from the radio head.

If you have the 12v all the time then the unit is powered as it should be.

Common problems are when the mast becomes stiff in operation and the electronics just cut the power before it has even started to lift up, the motor has got a build-up of carbonised grease on the brushes so it does not turn, there is a dry joint on the circuit board in the aerial box or someone has fitted a non-Jaguar radio that does not send the correct pulse to the aerial or a non Jaguar aerial mast that does not recognise the coded pulses.

Mellow
2004 (Facelift 05-MY) 4.2 Jaguar S-Type R in Black.

Morocco Red / Magnolia 4.0 Sovereign Auto Vin.708xxx.Insurance write off on Friday 13th March 2015.

abercanadian
Posts: 1327
Joined: Tue Oct 16, 2012 6:50 am
Location: Vancouver Island

Re: Aerial

Postby abercanadian » Tue Apr 07, 2015 4:41 pm

M-e-l-l-o-w wrote:
[snip] the motor has got a build-up of carbonised grease on the brushes so it does not turn


This happened to mine (Harada antenna btw) and I found the motor clogged as Mellow says ..good thing about the antenna motor is that it's held together with magnets and can be easily disassembled for cleaning by just "pulling the top off" :D

Larry
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Oyster Metallic/Doeskin on Aero Alloys
230,000 Kilometers 143,000 Miles
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94 XJ40 SOVEREIGN vin 703632
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111,000 Kilometers/69,000 Miles
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