Hello Class,
Today we are going to tacke rebuilding the Hirschmann Automatic Antenna. The Hirschmann comes in two flavors, Semi-Automatic and Fully Automatic. The Difference? That "ANT" switch up front that takes command of it and stows it or makes it go to "Half-Mast".
Why is it important to know the difference? Well Duh! It's MB and everything is different from car to car even when they are the same.
When I did my restoration, I did not know the diff at that point and the one on my car had a bent mast and so I just bought anouther used one off eBay which was in good condition and is in my coupe now. Since I had the car apart and I had a spare switch, I wired two extra wires, routed out the change cup for the switch and I was done. However, with the impending "Rear Sun Shade" installation, I need the two wires already laid back to the antenna for the shade control, plus of course the switch position itself. I had, when I did the antenna switch hoped that one day I would find a rear shade. Then Snibble came through with a GREAT DEAL and I scooped it up and it's on it's way now.
So I went to the junk yard and found the remnants of a fully auto ant. With a FAA, it has three wires basically. Brown for Ground, Red for power connected to a constant hot and that is to retract when you turn the key off. And Blue is the +12 trigger to command it up by the radio. This is connected to the Radio's "ANT" wire. The other two wired in the old style commands "Half" and "Down" on each wire. Not needed since I have a DVD/NAV system that commands the antenna only when the Head unit needs the signal.
The Sedan had a very new looking one that was the old style, but the case was in VERY good shape. So I opened it to look inside and it's gears were broken. The antenna has a weakness, rather safety that is it's Achilles heel. More on that later.
So I had a good electronics package from the one from the JY and I had a clean unit from the sedan, now to make them one.
First off take the antenna out. If you don't know how to do this, stop now. Do not go farther...
Next, You have to open the unit. Do it gently bu getting a couple of your little screwdrivers out and GENTLY prying the tabs in and up. Once you get one or two done get another LSD (Little Screwdriver) and slide it under the flat way and work out that side. Once you get the cover off there are three rubber grommets, collect them and DO NOT lose them.
Unscrew the antenna at the top of the mast IF you still have a mast in that is. Once it is loose, then pull out on the mast and you will see how it unreels. Hold the reel down a little with your hand.Once the mast is out undo the set screw that holds the guide mast in and unscrew the guide mast. That is that short aluminum tube that comes out of the black case. Careful to note and and all grommets and seals. Mine had two. One in each of the inner guide tube.
In the first pic you will see the basic layout. Unscrew the two motor screws in the center of the pic. That will separate the motor drive from the plastic cable housing. If yours is black like this, that means that (Like most of these) the inner cable bearing has worn a flat spot. Inspect and clean the worm gear on the motor drive. Clean these with a mild solvent or rubbing alcohol 91% and a old toothbrush. Remove the old drive belt and replace it with the one from the rebuild kit. Ger some "White Lightning Grease" from the auto parts store of your choice and you will lube this gear when you reassemble.
At this point I remove the control unit out of the JY one (the FA) and swapped it into the SA one. The plug slid out easily and the new one went right in. The + and - wires to the motor had a very convenient plugs too. Thanks MB and Hirschmann!
So I swapped the controls and plugs and reinstalled it into the unit. This one did not require the cleaning that the older one would have, had I restored that one in the pic. The one out of my sedan was fairly clean, but did need a little TLC. So I again cleaned everything in Alcohol.
Part 2 next post.
Today we are going to tacke rebuilding the Hirschmann Automatic Antenna. The Hirschmann comes in two flavors, Semi-Automatic and Fully Automatic. The Difference? That "ANT" switch up front that takes command of it and stows it or makes it go to "Half-Mast".
Why is it important to know the difference? Well Duh! It's MB and everything is different from car to car even when they are the same.
When I did my restoration, I did not know the diff at that point and the one on my car had a bent mast and so I just bought anouther used one off eBay which was in good condition and is in my coupe now. Since I had the car apart and I had a spare switch, I wired two extra wires, routed out the change cup for the switch and I was done. However, with the impending "Rear Sun Shade" installation, I need the two wires already laid back to the antenna for the shade control, plus of course the switch position itself. I had, when I did the antenna switch hoped that one day I would find a rear shade. Then Snibble came through with a GREAT DEAL and I scooped it up and it's on it's way now.
So I went to the junk yard and found the remnants of a fully auto ant. With a FAA, it has three wires basically. Brown for Ground, Red for power connected to a constant hot and that is to retract when you turn the key off. And Blue is the +12 trigger to command it up by the radio. This is connected to the Radio's "ANT" wire. The other two wired in the old style commands "Half" and "Down" on each wire. Not needed since I have a DVD/NAV system that commands the antenna only when the Head unit needs the signal.
The Sedan had a very new looking one that was the old style, but the case was in VERY good shape. So I opened it to look inside and it's gears were broken. The antenna has a weakness, rather safety that is it's Achilles heel. More on that later.
So I had a good electronics package from the one from the JY and I had a clean unit from the sedan, now to make them one.
First off take the antenna out. If you don't know how to do this, stop now. Do not go farther...
Next, You have to open the unit. Do it gently bu getting a couple of your little screwdrivers out and GENTLY prying the tabs in and up. Once you get one or two done get another LSD (Little Screwdriver) and slide it under the flat way and work out that side. Once you get the cover off there are three rubber grommets, collect them and DO NOT lose them.
Unscrew the antenna at the top of the mast IF you still have a mast in that is. Once it is loose, then pull out on the mast and you will see how it unreels. Hold the reel down a little with your hand.Once the mast is out undo the set screw that holds the guide mast in and unscrew the guide mast. That is that short aluminum tube that comes out of the black case. Careful to note and and all grommets and seals. Mine had two. One in each of the inner guide tube.
In the first pic you will see the basic layout. Unscrew the two motor screws in the center of the pic. That will separate the motor drive from the plastic cable housing. If yours is black like this, that means that (Like most of these) the inner cable bearing has worn a flat spot. Inspect and clean the worm gear on the motor drive. Clean these with a mild solvent or rubbing alcohol 91% and a old toothbrush. Remove the old drive belt and replace it with the one from the rebuild kit. Ger some "White Lightning Grease" from the auto parts store of your choice and you will lube this gear when you reassemble.
At this point I remove the control unit out of the JY one (the FA) and swapped it into the SA one. The plug slid out easily and the new one went right in. The + and - wires to the motor had a very convenient plugs too. Thanks MB and Hirschmann!
So I swapped the controls and plugs and reinstalled it into the unit. This one did not require the cleaning that the older one would have, had I restored that one in the pic. The one out of my sedan was fairly clean, but did need a little TLC. So I again cleaned everything in Alcohol.
Part 2 next post.
