Hello,

I am the proud new owner of a 1980 300TD. It has, so far, been all around a great car, except for one thing: It's cold. I've got no heater and no blower. This must be the most advanced (complicated) climate control system I've ever had on one of my cars. I'm not even sure where to start.

I didn't think it'd be a problem until Fall. When I bought the car, it's was mid-60s and sunny all day, I thought the worst was over. I was wrong, it's snowing right now. The lack on demist in the rain is downright dangerous, too.

So here's how it is:

I've got no blow from the vents, at least nothing I can control.

When the car is cold, I can hear the blower making a bit of noise (I'm assuming this Merc is like other European cars, in that the blower always blows a little bit, even when it's off).

The control panel does nothing. I can't even press in a few of the buttons.

I have some steam coming from the defrost and dash vents. I keep the dash vents closed and there's rags stuffed in the defrost vents to keep the windscreen from fogging up. There's a small leak from the heater core, I'm assuming this is the cause of the steam.

So I guess I'm wondering, since I'm new to this car, where I should start. I don't want to fire the parts cannon at it just yet, since time and money are not things I like to waste. My other cars have had completely mechanical heater systems, so I'm not sure where to begin.

There's the control unit in the engine bay, another thing in the bay, the blower motor, the control panel, the heater core. If anyone could share tests for these units or just general advice, I would be greatly indebted. I have an 82 parts car the ready, but have noticed that somethings with the climate system are different (the control panel and if the control unit is the same, it's in a different place and I haven't located it yet).

Also, if there is a method to swap or convert this system to a simpler, more mechanical system, I am all ears.

Thanks and sorry for the long post.