couple of problems......
 

on my 86 190e16v:

antenna doesnt work(no motor sound) when radio comes on. before i buy a motor.....any other suggestions?

cruise control doesn't work.

are these two linked? i replaced their fuses to no avail.

thanks

Probably no linkage there. For the cruise control, I would remove the circuit board and resolder every connection on the back of it. This has worked for me on at least two cars that I can remember. Bad solder connections are almost impossible to see even with a magnifying glass. So resolder all of them. Get yourself a pencil type of soldering iron.

As for the antenna, first thing I would do is determine if the thing is getting any voltage.

First check the fuses under the hood, As far as the antenna goes, go to the trunk and pull off the left side that protects the left rear quarter panel and 1st check for the ground wire, it that is connected take a lead tester and check for current coming to the unit, if you have current you could have a stuck antenna, then take I think a 13mm wrench and unscrew the antenna from the top and turn the radio off then on and while it is turning tug on the unscrewed antenna, if the motor is working the antenna will come out, then you need to just change the mast by leaving the radio on and pushing in the new antenna and turn the radio off and feed the mast in and screw on the cap, if no power and motor then you need to change out the entire unit. As far as the cruise control issue, first check for the fuse, then locate on the brake the release switch as that could be faulty or disconnected, then pull of the air cleaner and check the linkage, if that does not help, I would then obtain a cruise control amp, this is located under the dash just above the driver's left knee, pull off the plastic protecter, plug in your new unit and test drive, if that works, pull the dash off and swap out the unit.
Please post your results here.

The Diagnostic procedure mentioned above is what i would recommend.

Also just to give you a heads up if you find there is motor activity and just the teeth on the extend / retract gear inside the housing is bad the fix for that is a little pricey.

Since MB does not offer a rebuild kit or even just the gear alone you have to buy the whole motor assm. which can run upwards of $300 to $400 or more depending on model.

Just a heads up.