I don't know about the 126, but on the 124 the horn and climate control are on separate fuses. Did you try checking for 12V at the horn terminals? If you don't have the service literature, I highly recommend you get it. It will be invaluable for all your problems. Plus it has the entire electrical diagram.

__________________
2002 E320 T-sedan (210.282) 219K
1994 E320 (124.032) 252K (dearly departed in hit & run)
1988 260E (124.026) 301K (sold)

Yeah they are on different fuses in the fusebox, but I just wanted to know if the horn and blower motor shared wiring at any other point. I'm guessing that when I manually bridged the circuit at the ac relay, I shorted out some wire that supplies power to both the blower motor and horn. So does anyone know the relationship in wiring between the two, anywhere that they share wiring?

So I've been without a blower motor and horn for almost a month... Can somebody please help?

84MB500SEL
I would be happy to help you if I knew ANYTHING about Euro cars. I do know that I once worked on an 84 280SL and the A/C looked like yours and it was an aftermarket add-on. I have looked at the wiring for a car like yours except a US version and the horn and A/C have nothing to do with each other that I could find. The way to fix this type of problem is to take one of the problems (I suggest you start with the horn) and ignore the other. In other words, one thing at the time. When you fix the horn, if the blower still doesn't work, then work on that.
Maybe some of our EURO friends can help if you ask specific questions. For instance, ask "what else is powered by the horn fuse". If you get an answer, then you can check those things to see if they work or not. Let us know the answer and we can give some guidance with those facts.
I just looked and on a US 500SEL Fuse 14 feeds power to the horn switch in the steering wheel. The other side of the horn switch goes to the horns. The other things on Fuse 14 are the cigar lighters, rear window defroster, rear seat heaters and the trunk light. I have no Idea if your car is the same but you can check and see if this information applies to the Euro car.
Sorry I can't be more help.
Paul

__________________
84 500 SEL (307,xxx miles)

On the earlier W123 cars, the strip fuse is mounted inside the evaporator housing at the very top where it connects to the air inlet. I'm wondering since your 500 SEL is a Euro car, if your strip fuse isn't mounted there as well.

FYI: Running your fan at lower speeds will make the AC system work harder. The faster it runs, the more accurate temp indication the temp sensor will receive and thus cycling the compressor more.

__________________

Don't Chrome them; polish them

Where is the evaporator housing you speak of in the w126?

I mentioned the W123, but the W126 may have the same strip fuse; I don't know. The evaporator housing and fan housing are the same box under the passenger side of the dashboard. In the W123, the fan is mounted just below the right side of the evaporator. The thick wire that connects at the fan motor comes directly from the strip fuse. However, the strip fuse almost never goes bad, hence its out-of-the-way location.

__________________

Don't Chrome them; polish them

on the 126 cars the strip fuse did not arrive by the factory until 86 with the 420,300 and 560.it was offered as a modification part by benz to basically remove fuse 11 out of fuse box because conns in fuse box would not carry the heavy load and would melt the conns into the fuse box.you will need to undo the screws and lift up the guts of the fuse box and examine the wires leading to fuse 11 to see if they are intact.if they are you will need to trace wiring for hot side of fuse back towards terminal 15 on the ignition switch because one side of that fuse should be alive with the key on.

__________________
David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
http://www.w108.org/gallery/albums/A...1159.thumb.jpg