ctravis595

i've been having trouble getting my engine fan to turn on since i've done my engine swap.

first i tried applying 12v's to the fan manually and it didn't spin, so i ordered a new fan thinking it would fix the problem. fan still doesn't move at all

i've tried resetting the a/c diagnostic codes, at first i saw a 1424 code but upon research that refers to a charcoal filter? probably has nothing to do with my situation but i reset the system anyways

i read that unplugging the coolant temp sensor will make the fan operate in high speed mode constantly. the only thing that happened when i unplugged the coolant temp sensor is the engine temp on the dashboard doesnt work...


i tested the fuse labeled engine fan on the fuse diagram but had no luck. couldn't find the relay for the engine fan on my 02 cl500 chassis...

the car behaves as follows -

slowly rises to operating temp (5 minutes or so) and will stay around 95 degress celsius when cruising. but whenever i stop in traffic the temp will slowly rise up to around 100 sometimes even reaching as high as 105 celsius

i thought the coolant was pumping as the engine can maintain a good temp, just not at a stand still because the fan is bad. but the upper radiator hose seems a lot hotter than the bottom radiator hose, making me think that theres no coolant flowing at all? could bubbles in my coolant system cause a fan not to kick on? any help is appreciated

edit:i also tried rotating the relays on the driver side fusebox with no luck

more info: i connected a test light to the plug going into the radiator and got a positive reading. i also have the 4 pin fan plug with the fan control module built into the fan assembly. not the older version where there's an external fan control module underneath the headlight

tried holding down both auto buttons on the a/c to manually activate the fan with no success.. getting kind of frustrated

tjs44

I had the same problem,I thought it was just a relay but MBZ changed the whole fan system.Mine would turn on sometimes when I turned off the engine but would not turn on when it was running.Tom

ctravis595

i appreciate the feedback, i purchased a new oem fan assembly and i'm still getting the same results unfortunately....

ctravis595

forgot to recheck the fuse for the engine fan after replacing it, seems the old broken fan control module blew the fuse. making me think the newer fan didn't work either