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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 104
Registered: 6-2009
Posted on Wednesday, 21 August, 2013 - 05:58 am:   Edit PostDelete PostView Post/Check IP

When restoring the bodywork the bodyshop removed the electric aerial. It had always worked well but since then it didn't anymore.
So I decided to take a look and found only one wire attached to the aerial, the other wire nowhere to be seen. I dismantled the interior panel to get at the wiring and found quite a mess : in the past an alarm had been fitted to this car and I guess whoever did this wasn't to bothered about the quality of their work.

The green/red wire and green/blue wire had been cut of (in picture 1 I made a temporary connection). Instead there is now a yellow wire (picure 2) going to the aerial.

I tried connecting the original wires again but to no avail. There is no current on the green/red wire. When I connect the yellow wire (replacing the green/red one) and the original green/blue one, the aerial works but not as it should.

It will rise/lower when turning the ignition on/off with the radio off. When turning the radio on the aerial will retract and when turning the radio of it will rise. Changing over the wires doesn't work.

As it used to work, even with the bodged wiring, there must be way to have it work again.

Benoit

picture 1


picture 2
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Brian Vogel
Grand Master
Username: guyslp

Post Number: 607
Registered: 6-2009
Posted on Wednesday, 21 August, 2013 - 06:32 am:   Edit PostDelete PostView Post/Check IP

Benoit,

I don't know if this will help, but I hope it will.

The electric aerial in my car is not original, but has been wired to go up when the radio is turned on and down when the radio is turned off.

I have not looked inside the wing/fender to see what other wires might be there, but I can tell you that on mine a red wire is passed through an opening in the fender and is connected to terminal C2 (common 12V input) on one of the Lucas relays that's related to the climate control system.

I've always understood that aerials wired this way had a 12V "always live" electrical source and that the radio switch is the signal to another switch inside the aerial itself as to which polarity should be applied so that the motor either extends or retracts the aerial. There are limiting switches that cut the motor off when it has reached full extension or retraction.

On another car of mine the internal plastic cable that pushes or pulls the aerial had broken. It would still cut off when the radio was turned on because the whole cable could still be unwound into the permanently extended aerial and the limiting switch got tripped by the finger on the cable. However, when you turned either the car or the radio off, the motor would attempt to retract the antenna, but because the cable was broken it would then spin and spin and spin since the limiting switch for the "down direction" would never be tripped.

If you desperately need me to look inside the fender I probably can. I have the car up on jack stands, again, and with the right front wheel off working on the starter (again).

Brian
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 105
Registered: 6-2009
Posted on Wednesday, 21 August, 2013 - 05:05 pm:   Edit PostDelete PostView Post/Check IP

Hi Brian,

thanks for your help.

The problem with my system is that is has been bodged.

The original wires had been cut off and there seems to be only one wire(the yellow one) connected to the aerial. But with only this wire it will not work (altough it used to).


The yellow wire (which replaces the green/red one) seems to feed the current and the green/blue wire raises and lowers the antenna.
When I connect/disconnect the green/blue wire the antenna will raise/lower itself. When I turn the radio on the antenna will lower itself and raise again when I turn the radio off.

So the radio activates the aerial but in the opposite way. So the radio must be connected to the aerial.

If it's not too much work I would very much appreciate if you could see what the wiring on your car connects to.

Regards,

Benoit
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Brian Vogel
Grand Master
Username: guyslp

Post Number: 608
Registered: 6-2009
Posted on Thursday, 22 August, 2013 - 02:39 am:   Edit PostDelete PostView Post/Check IP

Benoit,

I'll see what I can do much later today. I've got to crawl under the car again today to keep doing starter related work.

Brian
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Brian Vogel
Grand Master
Username: guyslp

Post Number: 612
Registered: 6-2009
Posted on Friday, 23 August, 2013 - 05:37 am:   Edit PostDelete PostView Post/Check IP

Benoit,

Sorry for the delay, but other issues intervened yesterday.

I'm not certain that the following will help, but I hope it might. I could not figure out how to get access to the aerial motor without taking the wheel well out, and even then wasn't sure it would work.

Like I said previously, there is a red wire that is fed through a small hole in the inside fender into the engine bay that connects to the +12V source at a relay that is always live whether the car is running or not. If this wire is disconnected the antenna will not raise when the radio is turned on nor lower if the radio is turned off. If you connect it after you turn the radio either on or off the antenna will do as you'd expect.

This is what you see inside my right side foot well, with the pertinent wires brought to the front:

Radio Aerial Wires

The wires that "disappear" through to the fender are blue and green, respectively, and cannot be original because the aerial on this car is a replacement.

There is a blue wire that connects to the other blue "disappearing" wire. This has to be the signaling wire since if it's disconnected the aerial does not go up when the radio is turned on. In looking at the blue wire on the "loom side" I am presuming it is not original nor actually part of the loom. The insulation looks different and I think it comes directly from the radio, but have not traced that back.

There is a green wire with red tracer that connects to the green "disappearing" wire. I cannot for the life of me figure out what this might be, since it doesn't do anything related to the aerial whether it's connected or not.

Here are two additional shots of the "rats nest" of wiring in the foot well:

Wiring One

Wiring Two

In these two shots I hadn't yet brought the green and green with red tracer wires to the front of "the nest."

Brian
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 108
Registered: 6-2009
Posted on Saturday, 24 August, 2013 - 08:25 pm:   Edit PostDelete PostView Post/Check IP

Thanks Brian,

I'll print them out and compare it with my car. Hopefully it will make things clearer.

Benoit
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 139
Registered: 6-2009
Posted on Monday, 24 March, 2014 - 12:21 am:   Edit PostDelete PostView Post/Check IP

I'm still no further with the electrical aerial problem. It does the opposite of what it should do.

With the ignition on and the radio off :
- I connect the green/red wire and then the green/blue wire : the aerial goes up.
- When I disconnect the green/blue wire before the aerial has reached its maximum height, the aerial goes down again.

- When both wires are connected, the aerial goes up. When I then disconect the green/red wire, the aerial will stop at whatever height it has reached by then.

When I turn on the radio with both wires connected the aerial goes down again.

The green/blue wire is live.

I just can't see what the problem could be and would very much appreciate any help.
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John Grieve
Experienced User
Username: john116

Post Number: 28
Registered: 4-2012
Posted on Monday, 24 March, 2014 - 05:57 am:   Edit PostDelete PostView Post/Check IP

In the original Rolls Royce aerial, one of the two wires provided 12 volts for the aerial to go up, and the other provided 12 volts for the aerial to go down. In the older Silver Shadows prior to around serial 34,xxx, the was done with a switch on the dashboard. In the cars after this, it was automatically done via the radio and a separate relay that switched the 12 volts to either the up or the down side of the aerial motor. The motor was sourced (or based) on GM electric car antennas of the late 1970's.

Most electric antennas these days work slightly differently. They require constant 12 volts on one wire, and switched 12 volts from the other wire. When the switched 12 volts (from the radio) is applied, the aerial goes up, when this 12 volts is removed (Radio off) the aerial goes down.

You need to check which wire is switched 12 volts from the radio, and which is constant 12 volts. Some people try to wire it so that as soon as you turn the ignition on the aerial goes up, regardless of whether the radio is on or not.
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 140
Registered: 6-2009
Posted on Tuesday, 25 March, 2014 - 05:25 am:   Edit PostDelete PostView Post/Check IP

The green/red wire is constant 12V. The green/blue wire is 12V with the ignition switched on.
When I connect the green/red wire with the green/blue wire from the aerial, the aerial will go up and stay up when I turn on the radio.
If however I first turn on the radio and then connect them,nothing will happen.

I stil don't see how I can solve this (as it used to work)
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 155
Registered: 6-2009
Posted on Tuesday, 03 June, 2014 - 05:40 am:   Edit PostDelete PostView Post/Check IP

I'm still struggling with the electric aerial.
It used to work before the bodyshop took it off.

Ignition on - radio off : aerial rises
Ignition on - radio on : aerial retracts

I took another look at the aerial itself. It says Rolls Royce UD24718 Nippon.
I noticed it is different from the one featuring in the spare parts catalogue.
Also, it has no earthing straps as described in the workshop manual, although there is part of an earthing strap still attached to the lower mounting bracket inside the wheelarch.
The aerial unit itself doesn't attach to that lower mounting bracket.

Should the aerial be earthed and if so, where ?

Benoit
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Bob uk
Unregistered guest
Posted From: 94.197.122.88
Posted on Tuesday, 03 June, 2014 - 07:39 am:   Edit PostDelete PostView Post/Check IP

The aerial must be earthed for it to receive radio signals properly

Connect a fat piece of wire from body of aerial motor to ground

The aerial worked before so it will be a bad connection or something simple

The rats nest in your photos is about par for the course

Check scotch locks and crimped not original connectors

I see many more incorrectly done crimps than properly done

(Message approved by david_gore)
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 156
Registered: 6-2009
Posted on Tuesday, 03 June, 2014 - 07:27 pm:   Edit PostDelete PostView Post/Check IP

Where should the aerial be earthed ?
The workshop manual talks about an upper and lower earth, but I don't see where it could be connected.

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Bob uk
Unregistered guest
Posted From: 94.197.122.90
Posted on Wednesday, 04 June, 2014 - 05:49 am:   Edit PostDelete PostView Post/Check IP

Any handy screw on the motor case and the second earth goes under the wing where the mast goes through

Use maybe a copper washer

This makes the metal body of the car the ground plane for the aerial

Modern radios in good reception areas will work fine with out proper ground plane

The 2 earths is typical rolls-Royce just in case belt and braces over do it engineering

Which is what endears me to my car

Use grease to refit
Lots of grease helps stop water ingress

(Message approved by david_gore)
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 157
Registered: 6-2009
Posted on Thursday, 05 June, 2014 - 10:04 pm:   Edit PostDelete PostView Post/Check IP

I earthed the aerial, but the problem persists.

In the past someone bodged part of the wiring : the green/red wire had been connected to a continuously live wire, so it constantly gave 11,9V.
This setup caused the aerial going down when turning on the radio and vice versa.

I wired it correctly, with the green/red wire now connected to the other green/red wire.
The aerial now does nothing anymore.
These are the voltage readings I get :
green/red wire with the ignition on and radio on = 11,9V
green/blue wire with the ignition on and radio off = 11,9V
In all other cases the readings are 0,0V

What am I missing ?

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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1206
Registered: 6-2006
Posted on Thursday, 05 June, 2014 - 10:14 pm:   Edit PostDelete PostView Post/Check IP

Fit a changeover relay to the radio switched output so that it switches the aerial signal the other way around.other way around.

Early cars had an aerial switch where the facia / Auto switch is fitted on later cars.

These arials were manual instead of automatic.
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Bob Reynolds
Frequent User
Username: bobreynolds

Post Number: 93
Registered: 8-2012
Posted on Thursday, 05 June, 2014 - 11:00 pm:   Edit PostDelete PostView Post/Check IP

I don't know exactly how this aerial works, but from what you have said in your previous posts, it seems that the green/red wire is the 12v supply wire, and the green/blue is the direction wire (12v=up 0v=down).

It seems to me that the radio switch is at fault by putting out 12v when the radio is switched off, rather than when it is switched on.

Can you verify this? Forget about what the aerial is doing, just measure the voltage on the green/blue wire when the radio is switched on and when it is switched off.
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 158
Registered: 6-2009
Posted on Friday, 06 June, 2014 - 12:44 am:   Edit PostDelete PostView Post/Check IP

Bob,

the voltage of the green/blue wire is 11,9V with the radio off and 0,00V with the radio on.
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1207
Registered: 6-2006
Posted on Friday, 06 June, 2014 - 02:34 am:   Edit PostDelete PostView Post/Check IP

what radio is it?
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Bob Reynolds
Frequent User
Username: bobreynolds

Post Number: 94
Registered: 8-2012
Posted on Friday, 06 June, 2014 - 03:28 am:   Edit PostDelete PostView Post/Check IP

The fault seems to be on the radio then, rather than on the aerial. It could be that the radio has a choice of 2 aerial-operating wires and the wrong one has been chosen. Try to see if there is a spare wire at the back of the radio that gives out 12v when the radio is switched on and 0v when switched off. If so, that's the one that should be wired to the aerial.

If not, you could solve the problem by wiring in a relay to invert the signal, or put a manual switch in, or just wire it to the ignition so that it comes up when the ignition is switched on. To do this you would wire the green/red to a permanent supply, and the green/blue to the ignition circuit.
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 159
Registered: 6-2009
Posted on Friday, 06 June, 2014 - 04:28 am:   Edit PostDelete PostView Post/Check IP

Paul,

it is the factory Blaupunkt that my car(SS2) came with.

Bob,

the radio unit itself was never disconnected and as the aerial used to work before the bodyshop took it out, I guess the radio is OK.

I just followed all the troubleshooting steps as described in the workshop manual and measured the current at the aerial relay. I drew some arrows so you can follow the results from my measurements.

According to the manual, the aerial itself should be faulty. However, I know it works when I connect it to a live feed.
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John Grieve
Experienced User
Username: john116

Post Number: 31
Registered: 4-2012
Posted on Friday, 06 June, 2014 - 07:33 am:   Edit PostDelete PostView Post/Check IP

So the original aerial worked differently to 'new' aerial. The switchover was done by a relay (in your diagram a few messages above), so there was never a 'constant' 12 volt line required. Depending on the whether the radio was switched on or not the relay supplied voltage to one wire or the other. Effectively reversing the direction of the motor. The motor itself had limit switches built into the motor so that the motor turned off when it reached the top or bottom limit.

I know you say nothing has changed, but as a test, I would leave your green/red wire connected, and temporarily connect the other wire to a constant 12 volt source and test it.
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 160
Registered: 6-2009
Posted on Friday, 06 June, 2014 - 08:15 am:   Edit PostDelete PostView Post/Check IP

Hi John,

I did what you suggested : I left the green/red wire connected and connected the green/blue wire with a 12V feed.
It has solved part of the problem : the aerial will go up when turning on the radio. Result !
However, it will not retract when turning off the radio. The only way to get the aerial to lower, is by connecting the green/red wire with the 12V source.
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Bob Reynolds
Frequent User
Username: bobreynolds

Post Number: 95
Registered: 8-2012
Posted on Friday, 06 June, 2014 - 12:43 pm:   Edit PostDelete PostView Post/Check IP

This is what you would expect. The radio is now supplying power to the aerial via the green/red wire, so that when it is switched on it goes up because the direction wire is permanent 12v. It never will go down if the green/blue is at 12v. Switching the radio off will just remove the power from the aerial.

There is a basic incompatibility between the radio and the aerial. I am of the opinion that the green/red wire is the supply and must be connected directly to a 12v supply (preferably via the same fuse as the radio is powered from). Without power on this wire the aerial will not move in either direction.

As for the green/blue wire, that needs 12v when you switch the radio on. You say there is a relay between the two? Well the contacts of the relay must have been swapped over then. Somewhere on that relay there will be a contact that is 0v when the radio is switched off and 12v when it is switched on. You need to find that contact and connect the aerial green/blue wire to it. I would guess that it is a change-over relay and somebody has connected the green/blue wire from the aerial to the wrong side of the change-over contacts.
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Bob uk
Unregistered guest
Posted From: 94.197.122.77
Posted on Friday, 06 June, 2014 - 10:16 am:   Edit PostDelete PostView Post/Check IP

Disconnect green red??

(Message approved by david_gore)
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 161
Registered: 6-2009
Posted on Friday, 06 June, 2014 - 04:51 pm:   Edit PostDelete PostView Post/Check IP

Bob (Reynolds),
you solved it !

I swapped the green/red and green/blue wires at the relay. Still nothing. I then connected the green/red wire from the aerial to a live feed (bypassing the relay) and everything worked as it should.

It means there is probably still some fault with the original power supply of the green/red wire, but as it now all works, I shall leave it at that.

Thanks everyone for your help.

Benoit

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