fan controler

hi group have a 2004 clk 320 with fan running full speed have both powers and good ground have green and white lin wire need to know best test procedures

You really need to look at MB service info to diagnose that efficiently and successfully.

Well you could check coolant temp sensor in data pids and see what the computer thinks it is (maybe it's false high) , or a stuck relay in the fuse box , also a a/c high pressure switch could possibly cause this? Maybe try bi directional controls and see if you can turn it off that would tell you if the control module is in fact controlling it . But you didn't give much information in your post so I may be way off track on what's going on....

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+1 for checking temperature and pressure sensors.