Big Automatic Problem

I own a 1.6GL 1986 Automatic, it's a Cabriolet. Basically I have been driving in 2nd gear for about a month now.

I can manually use gears 1 and 2 and even Reverse, without a problem. However, Drive will not work.

If I go from second and then into Drive, it puts me back into 1st.  :?

Any help will be greatly appreciated.

When it first stopped working, I checked my transmission fluid, was hardly anything and dark. Filled up. Dipstick says it has enough fluid but the fluid is dark brown which isn't good.

When I get a good day free with good weather in the next few days I will follow the instructions of the sticky thread about changing the fluid and filters etc. Whether that will sort the problem I have no idea… any ideas or has anyone encountered a similar problem?

 

drain fluid, replace filter and oil with fresh stuff and see where that gets you. you might need a couple oil changes if its really grotty inside the box