auxiliary fan's fuse keeping burning

[dan dang]

I have a 91 300ce mercedes benz and the fuse for the auxiliary keep burning whenever i turn on the air conditioning. As i monitor engine, I saw that there is a coil next to the dryer keep getting really hot. Once that coil got so hot then the fuse is blown. Please give me some advice. Thanks a lot

[Arthur Dalton]

Fuse D or fuse 7 ???

[samiam4]

Check the fan motor!

As motors age and lubrication dries out, they draw more and more current.



Michael

[dan dang]

Originally Posted by Arthur Dalton

Fuse D or fuse 7 ???

fuse D

[Arthur Dalton]

OK

That [ D] is low fan load circuit.
Couple of easy test
1 . turn each fan by hand to see that they are both free.
2 .Check connections on each side of resistor, they burn and make a bad connection
3 . Take a jumper wire with an amp meter wired in series and jump from Bat+ to the terminal with 2 wires on it at resistor. This is fan draw and should not excced 25 A.. if it does , you have a bad fan motor .. if fine , Benz has upped fuse D to 25 A on double fan models.
Lastly, there has been wire problems between the relay and resistor for low fan , so check any for burnt at the relay end too..

[dan dang]

Originally Posted by Arthur Dalton

OK

That [ D] is low fan load circuit.
Couple of easy test
1 . turn each fan by hand to see that they are both free.
2 .Check connections on each side of resistor, they burn and make a bad connection
3 . Take a jumper wire with an amp meter wired in series and jump from Bat+ to the terminal with 2 wires on it at resistor. This is fan draw and should not excced 25 A.. if it does , you have a bad fan motor .. if fine , Benz has upped fuse D to 25 A on double fan models.
Lastly, there has been wire problems between the relay and resistor for low fan , so check any for burnt at the relay end too..

Can you please tell me where is the relay? Thanks

[Arthur Dalton]

Box behind fuse compartment .. have to take 6 screws out and lift the top

Easiest if hood is full tilt.
There are two [ high/low].. you want the one in slot 'B"