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Discussion Starter #1
Hi!

I last drove the Bentley on Sunday and then parked it up in its garage. Yesterday, I went to fetch something from the trunk and noticed that the central locking wasn't opening the doors. Turns out the battery had drained. The only thing out of the ordinary I found, was that the antenna hadn't fully retracted. Can that drain the battery in a couple of days?

Cheers

Es
 

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I would not be surprised that yes the antena did not stop trying to remote.
Can you put the radio ON without the key in the switch box ?
 

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Discussion Starter #3
Hi Jean,
No, I'm fairly sure that it's wired so that it will only switch on with the ignition on.
 

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Many ant are wired so when you turn the car off the ant will go down, so therefore it requires a relay to provide a hot path for the ant that is switched.
 

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Let's say, that most automatic antennas like Hirschmann, Beru, a lot of Chinese products, etc. will turn off even when the bat is not closed but blocked for some reasons. Usually there is additional clutch, overload switch or just timer. It will be pretty strange if RR antennas do not have any safety circuit.
 

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Discussion Starter #6
Hi!
I would have thought so too, but maybe the RR antenna needs a signal from the retracted position before it turns off?
I had drainage problems when I first got the car, but that was the light switch in the trunk.

If got the day off tomorrow, Ill investigate then.

Cheers

Es
 

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This topic came up on the RROC (US) Forum recently when a fellow had a mystery parasitic battery drain. After much searching it was discovered this was the cause. He replaced the antenna and the drain disappeared.
 

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I have dealt with several aerials that were "constantly hot" and that cut off their own power when they couldn't "pull down" any more segments of antenna. That was probably secondary to some sort of limiting switch that is on the flexible "whip" that pushes/pulls the antenna, and near the end for the final skinny portion of the antenna.

The one on my Buick is now permanently extended, by me, because the whip broke and it will run, perpetually, trying to lower the antenna and never detects that it has reached the "end of the antenna" and just keeps going and going and going.

So, short answer, yes, I absolutely believe you could have an antenna motor drain your battery under specific circumstances. And after you have it charged up it's easy enough to test whether yours is in the "De-Energizer Bunny" state as mine would be if not disconnected.
 

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I had this last year with my aerial, it had become stuck and was producing a constant wurring noise from the boot.

I could not switch it off, even ignition off, and flipping the battery switch in the boot! In the end I had to fully disconnect the battery to stop the motor from burning out.

The aerial itself had 2 live wires off it, a 12v from the radio where it detects a signal it goes up and a constant live from the battery for when the radio turns off provides power to bring the aerial down again. This is always on so certainly could be draining your battery.

Replacements are fairly reasonable, I got a Hirschmann off eBay for about £50 which was a direct fit.
 

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Discussion Starter #10
Hi detomaso,

I'm fairly sure this is also my problem!
What model Hirschmann did you get, do you remember?

Cheers

Es
 

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Just looked at my emails and it wasn’t an official Hirschmann but this was what I purchased:

 

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The electric aerial, regardless of the car it's on, should occasionally be cleaned when extended with a soft cloth and, if you so desire, using something like Simichrome polish (optional, definitely optional).

Afterward wipe it with a piece of paper towel that's been moistened with silicone lubricant. Doing this every once in a while extends the life of an electric aerial by quite a bit.
 

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Discussion Starter #14
Hi,

I was just back at the car, and unfortunately the battery had drained again 😪
I checked the light in the trunk, as that was the problem previously, but it switches off as it should.
Any ideas?

Cheers

Es
 

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The principles involved in checking for a parasitic drain are the same no matter the make of the car, and it's clear that you have one. I really liked this particular YouTube video:

How To Perform a Parasitic Draw Test - EricTheCarGuy

and there are many others. You're going to have to chase down what circuit the drain is occurring on, then removing things from the equation from that circuit until it stops. Then you've found your culprit.
 

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Discussion Starter #16
I fear that you're right....
I'll summon up courage at the weekend - I've switched off the battery master, maybe that helps some!
 

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Discussion Starter #17
Hi!

I think I've found the culprit: when driving the car this morning in the dark, i noticed a thin sliver of light around the glove box. One of my driving gloves was stuck between the lid and the frame, which caused the light to remain on....
I'll observe further, but hope that I've found the problem!

Cheers

Es
 

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Good to hear.

Not that one shouldn't be tracking down this sort of issue anyway, but this is also one of the reasons I've been replacing lamps in all my cars with their LED equivalents (or betters, in many cases - the trunk/boot in my daily driver now looks like it's lighted like a football field with an LED strip rather than a single bulb).

They not only last much longer, they throw much, much more light with a far smaller draw, so if this sort of thing does happen the battery does not drain nearly so quickly.
 
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Are the driving gloves the perforated brown leather and wool type that cad's like Terry Thomas would wear driving an old British sports car? Well Heloooo:D
 

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Discussion Starter #20
😅🤣🤣😅

Perforated leather - full-on cad 😁
 
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