96 C 280 Air Conditioning

Just purchased a C 280 and the economy light is on for the air conditioner so the compressor will not come. I put freon into the system, not knowing that the compressor won't come on with the economy selected, but I push the button again and the air flow either goes up or down, but the light stays on and the compressor doesn't engage. Is there a possibility that the compressor is frozen/broken or is there something else that I am not doing. I don't have the owners maual and looked online, but only found a manual for a newer model. Thanks for the help in advance.

I found what I think is the Mono Valve and wanted to know if this is bad, will it prevent the EC light from going out? I would hate to spend the money and then not have it fixed.

I had time to play with switches today since it was a down pour when I got home and here is what I found out. I held the recirculate switch and the EC switch at the same time for approximately 10 seconds and the EC light went out. I thought it was a fluke so I pushed the EC light and it was on again and would not go out by pushing it again. I held the two switches again and the light went out. Then I lifted the hood to see if the compressor was engaging, so I hooked up the freon hose to try to put more in and I heard the compressor kick on. The air isn't as cold as I was expecting, but it's not hot. I may have a leak, so at least now I know that I won't have to sweat too much in the next couple of days with the temps going up here this week. I hope this will help someone else.