I am buying one of these–long story how I got this kind of car–and I have some questions, about how to operate some controls. I downloaded the Owner’s Manual, which doesn’t always help. (It was the only book missing from the stack I found in the glove compartment.)
I don’t know what kind of fuses the car uses–ceramic, glass with metal at both ends, or what.
It doesn’t seem to have a “door key,” and the manual give a rather confusing description about what locks/unlocks what, other than the ignition switch and the trunk.
What make is the radio that is installed at the factory?
I don’t know what kind of fuses the car uses–ceramic, glass with metal at both ends, or what.
The fusebox should be under the hood – you can lift its cover and see. It should have blade fuses.
It doesn’t seem to have a “door key,” and the manual give a rather confusing description about what locks/unlocks what, other than the ignition switch and the trunk.
This doesn’t make sense to me. Do you have a key that works in the ignition but not in the doors? I’d expect it to have a (master) key for the ignition, doors, glovebox (if lockable), and trunk; and possibly a valet key that doesn’t access the trunk or glovebox.
What make is the radio that is installed at the factory?
Decades ago it would have been Blaupunkt. Nowadays I don’t know.
Thanx 
No, I can’t get the ignition key to fit into the doorlock.
As in the key won’t physically go into the hole? I think with this style of key, the wrong key should still go into the lock, it just shouldn’t turn. So if you can’t get it in, the lock cylinder is probably broken or has something jammed in it. You might try probing in there with a paperclip or something to see if there’s maybe a broken-off key in there.
Does this car have a key hole on the passenger side? Does the key work over there?
Good question. I’ll try it.
There is no key slot on the passenger - side door.
Besides, the key will go in the driver’s side door completely but will not turn.
It’s quite possible the ignition lock has been replaced, but the owner opted not to re-key either the ignition lock or the door locks.
Does the key fit the glove-box lock (it may be a lock on the center console)? That lock should be keyed the same as the door and ignition.
I think these cars also came with a “Valet Key”, which would work the door and ignition, but not the glove-box lock or the trunk lock.
Yes, the former owner had specific repairs made on the ignition switch–and gave me the receipt. I don’t have it at hand, it’s in the car.
Perhaps something on that receipt (work record?) would give me a clue?
But the same key works in the ignition and the trunk right? It would be really odd if someone had to replace the ignition lock and got a matching one for the trunk but not the door.
With old cars with remote locking, sometimes you can get issues with the door lock corroding or gumming up because nobody ever uses it (and of course this time of year it could be frozen if you live in the right climate.) You could try very carefully turning the key with a little bit more force to see if you can work it loose.
Then you probably shouldn’t be shopping for fuses until you locate the fuse box, at which point all will become clear.
Unless the seller said “Oh, [problem] is just a blown fuse],” and you’re looking to be ready to fix it the moment you get the car, in which case your should be shopping for replacement wiring harnesses before fuses.
I’m guessing the OP has the valet key and the previous owner had a trunk key cylinder installed in the driver’s door?
Probably Becker. In fact, it was probably Becker decades ago, too. Blaupunkt were factory fit in all the other German makers, but never Mercedes to the best of my recollection.
Correct. At least as far as Mercedes. My 73 280 had a factory Becker radio. Also my 1999 Porsche had a factory Becker radio as well.
Last night I checked the lights ( headlights, etc.) and found that just before the ignition switch was in the starter position all kinds of things lighted up on the dash. Including the radio, which I have been, of course , mostly clueless about.
I had been wondering whether things such as the odometer and speedometer ( and fuel gauge) were connected to fuses–the former owner’s grandfather said some were blown–but I’m not so sure now…
The odometer and speedometer should be mechanical and independent of any other wiring. Think about it: if you could shut off the odometer by pulling a fuse every car would have 150 miles on it when it was sold again. I’m not sure how fully electronic odometers work, but I don’t think you have one.
Probably referring to the fuses that supply power to the lights that illuminate the speedometer, etc. Or maybe to the bulbs themselves.
You should really joun the Mercedes Owners Club http://mbca.org/. They will have all the information that you need.
Thanx. 
On cars with digital odometers (which I think this car actually does have) the mileage value is kept in the engine computer. The gauge cluster is probably all-electronic and, assuming nothing else critical runs off the same fuse, you could drive around with the gauges off if you felt so inclined. The car will still rack up miles because the mileage value is handled by the computer, you just won’t be able to see them.
I got a look at the fuse box under the hood. The printed list on the underside of the box lid doesn’t mention a “horn,” but it does mention a “fanfare,” whatever that is. Whoever translated the fuse list did not have a very good command of English.