Hello,

I have a 1978 300-cd. I was driving last week and while stopped at a red light a hairline tail of smoke came out from under where the horn is on the steering wheel. I immediataly associated the smell with that of electronics. It stopped after like 10 seconds but the smell lasted. All the electronic switches work, after i tested them after. Then a week later the smell came back strong again, this time i heard some weird clicking to the right of the radio. And agian everything works fine.

Any suggestions?

This could be alot of different things. Is your ACC fan working? How about the climate control itself? There is an electrically powered auxiliary water pump that can take the climate control circuit board out if it seizes. It could also be the climate control servos that actuate the vacuum pods to open and close the air flaps in the climate control airbox.

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Doug

1987 300TD x 3
2005 E320CDI

Well the AC unit stopped working about a month ago. And i did notice recently that the heat has been flowing through the vent even though it is turned off. Come to think of it it has been hotter in the car since the first electric smell.

How should i proceed? Is this a fix an intermediate car mechanic can do or do i bring it in?

Is there a danger of driving it still?

thanks!

Check your fuse box. When I had smoke inside the cabin, I found the aux fan fuse melted the plastic around it. The fuse didnt blow but created a lot of heat to burn the plastic. Could be other things like a short . Id have it checked.

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'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

If you do keep driving it, make sure all the fuses are of correct size in their respective slots, I had found 2 of mine overrated by a P.O. If you find a melted one or one that appears to have been really hot, pull it out until you find out why. if nothing is evident of heat, make sure you have a dry chemical fire extinguisher in the car just in case. (small ones for cars are easy to get)