87 mercedes 190d wont start, help appreciated

[jussumguy]

I've been the owner of a mercedes turbo diesel for almost a year now and have had no problems until recently. it had been driving perfectly fine since i bought it and one day after i brought it home, i tried starting it up again and nothing happens. wen i turn the key all the way over it jus makes a clicking noise and doesnt turn over the engine or anything. it's not a constant clicking noise but jus one click and then nothing. i thought it was the starter so i bought a new one and jus took out the old one today. rather than putting the new starter all the way in i jus connected the wires ta make sure that was the problem and still nothing happens. jus a click and thats it. could it be the ignition? any other ideas?