Need Help testing cooling fan motor & module
Thread Starter
Senior Member
Joined: Feb 2020
Posts: 331
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1998 CLK 320
Need Help testing cooling fan motor & module
Hello all,
I replaced my radiator and as I was bleeding the system, I noticed that the fan wasn't turning on. I saw that the fusible link (at the battery) was blown. I bypassed the fuse (for testing purposes) and the fan works, but I couldn't confirm max speed. Before I replace that fuse, I was hoping to test the fan motor and the control module.
Can anyone help me diagnose the health of the fan motor and the control module?
Any and all help is appreciated.
Thanks!!
I replaced my radiator and as I was bleeding the system, I noticed that the fan wasn't turning on. I saw that the fusible link (at the battery) was blown. I bypassed the fuse (for testing purposes) and the fan works, but I couldn't confirm max speed. Before I replace that fuse, I was hoping to test the fan motor and the control module.
Can anyone help me diagnose the health of the fan motor and the control module?
Any and all help is appreciated.
Thanks!!
Last edited by convicted; May 31, 2022 at 03:45 AM.
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
This sentence does not make sense. Before I replace that fuse, I was hoping to test the fan motor and the control module.
If you knew that fuse controlled the fan, how did you think it would come on?????????????
If you knew that fuse controlled the fan, how did you think it would come on?????????????
Thread Starter
Senior Member
Joined: Feb 2020
Posts: 331
Likes: 40
1998 CLK 320
I was able to confirm that the fan works, by (temporarily) bypassing the fusible link, but I only noticed the "low speed" setting - even when I turned the A/C on. What I'm hoping to do is confirm that the control unit (on the shroud) is working properly (IE: capable of increasing fan speed when it's supposed to).
Better?
Thread Starter
Senior Member
Joined: Feb 2020
Posts: 331
Likes: 40
1998 CLK 320
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
If the fuse is not blown again, then simply monitor the suction fan actuation. If the fan kicks in at minimum speed, there is no doubt the fan will kick in at maximum speed when it is required.
Simply look at temperature on the Inst. Cluster.
Simply look at temperature on the Inst. Cluster.
Thread Starter
Senior Member
Joined: Feb 2020
Posts: 331
Likes: 40
1998 CLK 320
