The inexpensive digital meters really are the way to go IMHO. For no more than $20 these can be had. They are highly repeatable which is what is important in diagnosing automotive electronics. They also have a pretty wide range. If I had a $100 lifetime limit on the value of tools that I own (oh thank you good Lord that this is not so) a $15-20 DMM would be in that group. It's pretty useful around the house, too.

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'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

I haven't torn into the trunk of my SDL but on the 123, you remove the plastic trunk liner on the left-hand side to expose the antenna mechanisim. You should be able to find the wiring connection for it in there somethere. Unplug it and you'll be golden.

I doubt if it's the alarm because, even if the audible warning was somehow disconnected and the alarm was triggered, your headlights would probably be flashing.

Be sure and check all the usual culprits: glove box light, trunk light...et al, ad nausaeum.

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Never a dull moment at Berry Hill Farm.

We disconnected the battery ground strap and put a simple test light in. One end is attached to the negative battery post and the other end connected to the cable that was on that post. You might need to pull the clock fuse to get the test light to go completely out.

Open a door or turn on anything electrical and the light will burn brightly. Your goal is to have no test light burning when all doors are shut and no electrical component is on. Pull one fuse at a time untill it goes out completely and then look for the items that work from that fuse.

Too easy, eh?

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You can get farther with a smile and a gun than you can with just a smile.

1984 300D
1985 300CD
1980 300SD
1993 SL500