97 E420 overheating issue
 

All

I have a 1997 E420 that needed it's condensor replaced. During the diagnostic process, my Mechanic (whome I trust) identified that the auxilary fans were not engaging.

The fans themselves run because I connected a jumper box to the fan itself and they engaged. I understand that there is a module under the fuse box. I also understand that there is a relay somewhere near the drivers side fog lamp. When testing the connection by putting a test light, I could see a pulse (test light would flash for a second and go out every 10-15 seconds) of electricity go to the fan but no constant power.

What should i Replace. Also, in 95+ degree temperature, are the aux fans needed only when the A/C runs or can the engine driven fan cope with the heat. I noticed that even with the A/C off, the temperature still creeps up. Shall I order a new fan clutch?

Any advise would be gratefully appreciated.

Checkout the steps in MENU#17 in the aqua table.

The flashing of the test lamp is the starting mode of the fan control module.

I would substitute a known-good fan. That it runs with 12V applied does NOT imply that the fan motor is good.

I don't understand?

Click the link in my signature . . got to Menu#24. . click on the number. . . read all of the things that you can try to fix the problem.

The suggestions will not fix the Aux fans but will ensure a low as possible engine operating temp. Changing the VFC will not do much since they don't cutin until the engine temp is very high.