420 SEL Radio Antennae

I've just purchased a 91' 420 SEL and the radio antennae doesn't go up.

And you can't pull it up by hand either.

The owners manual (radio) mentions a switch that, on some cars, is located above the radio that controls the antennae.
This car has no such switch.

Is there any such switch and, if so, where might it be located?

Or is the problem possibly a bad motor or?

Any thoughts on how to troubleshoot?

Thanks in advance for any help/ideas...

Make sure it's not a fuse or something first, I thought half my interior wasn't functional untill i replaced a fuse, and, wow, it works!
The switch is just to the right of the emergency flasher switch on the top of the center panel above the a/c controls, if you have it(I think you should on a '91)
You can access the antenna motor simply by pulling the side of the trunk trim out, it's attached by two clips at the top, and that's about it.
To remove the antenna, unscrew the mounting ring on the outside of the car; it might take some creativity to get this off, but shouldn't be to hard, just twist it counterclockwise, i think that's all you have to do. Also, from what i remember there's a screw on the motor assembly that holds the antenna mast in, i think it's brass colored. You should be able to pull the antenna mast off now and grease it, etc. if needed.
With the antenna out, turn on the radio and make sure the switch (if you have one) is in the up position. Go to the back of the car and listen for the motor. You should be able to hear it, if you don't, you probably need a new motor; assuming it's not a fuse or faulty wire (i'd hope it isn't).
Note: Don't pull too hard on the plastic wire that goes inside of the antenna mast and pushs/pulls it- I pulled mine too hard, snap... new antenna.
If needed, you can probably order a new antenna from partshop, or I know capitolwest.com has them.
That's about all of my knowledge concerning antenna's, mine didn't extend all the way when i first bought my '88 420SEL. Keep The Big Benz Rollin'

P.S. Probably my longest post ever!

[stevebfl]

And a well done, long, post.

Not much to add other than the switch for the antenna should be in the group of rockers at the top of the console.

It is really only a height control, but it can put the thing all the way down. I thought all US models had the height adjustment, could your car not be a US model? Euro models didn't have a height switch. This was originally put on US models because MB was having problems with receiving signals from a distance. This would interfere with local reception. It was considered that frequencies were to close in the US and thus the height adjustment to restrict reception.

There is no rocker panel for height adjustment, and I don't believe its a European model. I checked with an electrical tester today and power is getting to the motor of the antennae, but the motor isn't working.

So I took off the cover of the motor to take a look. I hand-turned the belt inside to get the antennae to raise about 1/2 way, or so, and then there was too much resistance.

I suspect the motor needs replaced, and was possibly done in by the resistance. I'll probably replace the whole unit.

[stephenson]

My 91 350 SDL does not have a height adjuster - my 85 300CD did. Not sure why it is different or why they deleted - perhaps considered it to be redundant (I kinda agree).

I took antenna housing apart - plastic, toothed drive cable was broken. I got new mast which includes the drive cable. Put it in, carefully lube, but not too much.

Has worked fine for about two years - it sounds as it it may need some fine lube on the outside to allow tubes to slide more easily.

Easy repair - except banging around the liner pieces in the trunk.

George