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Mercedes 1977 450SL
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Discussion Starter #1
I took the antenna out and opened it up. I noticed the pulleys inside are rusty and corroded but they still turn. The plastic cord (or guide?) seems to just slide between the gear and the pulley. Are these two things (the large gear and the pulley) replaceable and if so where can I get them.

The other question is that Droidster helped me with checking to see if it still even worked. Following the instructions of Cushjbc, we wired it up and the antenna works fine. We also checked the voltage of the power going back to the antenna and the meter shows it is giving off a constant 11 volts...could this be the reason why the antenna does not work? Nothing happens when the radio is turned on or when you attempt to manually manipulate the antenna with the switch on the dash.
 

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1967 250 S (sold) 1986 560 SEC 1987 560 SL
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No expert here but I've been inside a few of these, cleaned and relubed the works, tested antenna mechanism with 12 v working fine, only to realize it was the circuitry that was the problem. Tried re soldering, failed. Ended up just buying the cheapo antenna that goes up with radio on, bypassing the dash antenna switch.

best,

John
 

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1973 450 SL
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Can you check the wires at the radio (original / aftermarket ??) and the antenna switch. Did I send you the 77 ETM page for this?
 

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Mercedes 1977 450SL
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Discussion Starter #4
Can you check the wires at the radio (original / aftermarket ??) and the antenna switch. Did I send you the 77 ETM page for this?
Both are original...or at least they look like it to me. What's the deal with the 11 volts at the plug?
 

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1973 450 SL
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What's the deal with the 11 volts at the plug?
The antenna is connected to the battery bus (hot at all times) through fuse 1. So the red wire at pin 1 should read whatever your battery is producing. 11 volts is OK when the engine is not running; voltage will likely increase with the engine running due to voltage regulator. This part of the circuit enables the antenna to retract after you turn the ignition off.

I recommend testing voltage at the blue with red hash wire that comes from your radio into pin 1 of your antenna switch. This lead should have 11-14 volts when the radio is switched on. Old two piece Becker systems have an amplifier mounted behind your glove box. If you can pull your glove box liner out, it is easy to see. Becker chose to power the antenna (and other peripheral devices) from the spade plugs on the amplifier. If you don't have power on this lead when the radio is on, try changing the lead at the amplifier to the other 12V spade plug. If there is a power problem, the amplifier seems to be the most likely culprit.

If you are getting power at the antenna switch, test the switch pins reference the notes on the ETM page I posted and don't get zapped.

Good luck with it,
 

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Mercedes 1977 450SL
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Discussion Starter #6
The antenna is connected to the battery bus (hot at all times) through fuse 1. So the red wire at pin 1 should read whatever your battery is producing. 11 volts is OK when the engine is not running; voltage will likely increase with the engine running due to voltage regulator. This part of the circuit enables the antenna to retract after you turn the ignition off.

I recommend testing voltage at the blue with red hash wire that comes from your radio into pin 1 of your antenna switch. This lead should have 11-14 volts when the radio is switched on. Old two piece Becker systems have an amplifier mounted behind your glove box. If you can pull your glove box liner out, it is easy to see. Becker chose to power the antenna (and other peripheral devices) from the spade plugs on the amplifier. If you don't have power on this lead when the radio is on, try changing the lead at the amplifier to the other 12V spade plug. If there is a power problem, the amplifier seems to be the most likely culprit.

If you are getting power at the antenna switch, test the switch pins reference the notes on the ETM page I posted and don't get zapped.

Good luck with it,
Thank you Brad. my plug has 2 red wires going to number 1 and I think 3 blue wires going to 2, 4, and 5 separately. The voltage stays at 11 regardless of engine on or off and/or with manual manipulation of the switch on the dash.

So if I understand you correctly, there is an amp behind the glove box and whatever port the power is plugged into it, that one may be bad and if I move the plug to a different port it may work again?
 

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1973 450 SL
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If you have a Becker Mexico Cassette Vollstereo or a Becker Europa II, you have an amplifier behind your glove box. Before you go to the trouble of looking at that, pull your antenna switch and test for 12V at pin bushing 1 (female) of that receptacle when the radio is on. There should be no voltage at pin bushing 1 of the antenna switch receptacle with the radio off.

You are saying that you have 11 volts at the antenna receptacle (connector 135 in the ETM), but you are not saying which pin bushing(s) you are testing. It is normal to have 12ish volts at all times at pin bushing 1 of the antenna power receptacle. The only other pin bushing location I can read reliably on that ETM page is a .75mm blue with grey hash wire at pin bushing 2. The other wires are 1.0mm brown ground, 1.5mm blue, and 1.5mm black. The blue/grey, blue, and black voltage depends on the position of the antenna switch and I am not able to tell you what they do other than power the 3 solenoid switches inside your antenna.

If you open the covers on the antenna power receptacle (female) and the antenna plug (male), you can match the pin bushings and pins as follows:

1 Red & Red/Yellow/White bushing connects to Red pin at the antenna plug
2 Blue/Grey bushing connects to Yellow/Green pin at the antenna plug
? Blue bushing connects to Black pin at the antenna plug
? Brown connects to Brown . . .
? Black bushing connects to the remaining pin in the antenna (white if memory serves)

The second red wire you speak of coming from pin bushing 1 of the antenna power receptacle is a power wire for the trunk light. It should be a .75mm red with yellow and white hash.

I would so much rather supply pictures of this, but I don't have your antenna setup and the salvage work I have done is from 116s where the wiring differs a little. I realize the details are painful to read but I am trying to be as clear as I can in this description.
 

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Mercedes 1977 450SL
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Discussion Starter #8
If you have a Becker Mexico Cassette Vollstereo or a Becker Europa II, you have an amplifier behind your glove box. Before you go to the trouble of looking at that, pull your antenna switch and test for 12V at pin bushing 1 (female) of that receptacle when the radio is on. There should be no voltage at pin bushing 1 of the antenna switch receptacle with the radio off.

You are saying that you have 11 volts at the antenna receptacle (connector 135 in the ETM), but you are not saying which pin bushing(s) you are testing. It is normal to have 12ish volts at all times at pin bushing 1 of the antenna power receptacle. The only other pin bushing location I can read reliably on that ETM page is a .75mm blue with grey hash wire at pin bushing 2. The other wires are 1.0mm brown ground, 1.5mm blue, and 1.5mm black. The blue/grey, blue, and black voltage depends on the position of the antenna switch and I am not able to tell you what they do other than power the 3 solenoid switches inside your antenna.

If you open the covers on the antenna power receptacle (female) and the antenna plug (male), you can match the pin bushings and pins as follows:

1 Red & Red/Yellow/White bushing connects to Red pin at the antenna plug
2 Blue/Grey bushing connects to Yellow/Green pin at the antenna plug
? Blue bushing connects to Black pin at the antenna plug
? Brown connects to Brown . . .
? Black bushing connects to the remaining pin in the antenna (white if memory serves)

The second red wire you speak of coming from pin bushing 1 of the antenna power receptacle is a power wire for the trunk light. It should be a .75mm red with yellow and white hash.

I would so much rather supply pictures of this, but I don't have your antenna setup and the salvage work I have done is from 116s where the wiring differs a little. I realize the details are painful to read but I am trying to be as clear as I can in this description.
Thannks Brad. I will check this once the antenna is opened in front of me. In the mean time, should the mast have "teeth" on it or is it pretty smooth. I saw a replacement for another car and it has very aggressive teeth on it.
 

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1979 450 SLC 5.0 #1382 & 1966 200D
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Hi My First 450SL,

I did some work on the antenna in my 1979 450SLC 5.0 and replaced the old, broken mast with a new one. It did *not* have any teeth and needed a short portion of the white "rope" trimmed away so the antenna would retract all the way into the body of the antenna mechanism.

I cleaned away all the gunk, lubed everything up with white lithium grease and yes, there should be tension between the toothed ring and the idler wheel, which presses the antenna cord/rope against the drive wheel to make it go up and down.

You can find further details here:

Vintage Hirschmann Antenna Investigation & Repair

I bought my replacement mast from Antennamastsrus:

Item name: Mercedes Chrome Smooth Power Antenna Mast
Item number: A107
Quantity: 1

Let me know if you have any additional questions. Happy to help if I can.

Anthony
 

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1973 450 SL
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Yep - circled in red are two 12V sources of power for antenna, a Becker cassette deck, a traffic radio, other things that 1970's Europeans wanted to power.

Have you tested the lead into pin 1 of your antenna switch?
 

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Discussion Starter #12
Yep - circled in red are two 12V sources of power for antenna, a Becker cassette deck, a traffic radio, other things that 1970's Europeans wanted to power.

Have you tested the lead into pin 1 of your antenna switch?
Not yet, have to borrow a meter from Droidster tomorrow.
 

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Mercedes 1977 450SL
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Discussion Starter #15
Yep - circled in red are two 12V sources of power for antenna, a Becker cassette deck, a traffic radio, other things that 1970's Europeans wanted to power.

Have you tested the lead into pin 1 of your antenna switch?
So I tested everything as suggested and was able to get 11ish volts out of the constant, but nothing when the manual dash switch is engaged. I replaced the center A/C vent boot and had to remove the glove box lining. Behind it was the amp for the radio so I pulled that and the radio out and traced all the wires. I noticed there was one wire that was not connected and once I pulled the amp out it was the power antenna trigger output. Plugged it back in and antenna worked fine...with except of coming back down. When radio is on or the manual switch is engaged the antenna goes up about a foot but no further and does not retract. If I pull the smallest tip of the antenna a bit it will then retract and go up again to the same height (about a foot). Do I need to replace the mast? If so, how do I do that? It is under all the gears and pulleys
 

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1973 450 SL
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I think I posted the ETM page for your car reference the antenna switch. I think there is a note that says if the antenna switch is in the center position, the antenna will only raise to a height of 12". You can modulate the height from there using the switch, or place the switch in MAX and it is supposed to run to its full height.

What luck with the antenna switch?
 

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Mercedes 1977 450SL
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Discussion Starter #17
I hear the motor running but the antenna neither goes up or comes back down...unless I help it a little. Should the mast have any teeth on it?
 

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1973 450 SL
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If it's a 6000H or 6000U, the mast tape will be smooth. A 6000 EL tape has teeth. When you opened your case, did you fully disassemble the drive magazine? If not, it will have a black grime in it that makes the smooth tape slip on the drive.

Clean that sucker out! You may still need a new mast because the nylon wears down over time.
 

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1979 450 SLC 5.0 #1382 & 1966 200D
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Did you get a chance to read my reply to your thread?

Your antenna mast appears to be "toothless" like mine.

I'm just going off the picture in your original post because I can see a whip-tail antenna cord between the idler wheel and the drive wheel.

I think your antenna needs a toothless mast but only you can be sure.

After reviewing the pictures in my antenna thread and yours, I'm quite sure you need a toothless antenna mast.

I agree that you need to clean up the works and degrease the drive wheel to make sure it has adequate grip/friction/purchase against the new antenna mast, as per cushjbc.

Onwards,

Anthony
 

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Discussion Starter #20
Did you get a chance to read my reply to your thread?

Your antenna mast appears to be "toothless" like mine.

I'm just going off the picture in your original post because I can see a whip-tail antenna cord between the idler wheel and the drive wheel.

I think your antenna needs a toothless mast but only you can be sure.

After reviewing the pictures in my antenna thread and yours, I'm quite sure you need a toothless antenna mast.

I agree that you need to clean up the works and degrease the drive wheel to make sure it has adequate grip/friction/purchase against the new antenna mast, as per cushjbc.

Onwards,

Anthony
Thank you for the reminder. I did read it and forgot. What should I use to clean it? Brake cleaner?
 
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