The complete automotive resource for buyers, sellers, and owners like you.
Car, Truck and SUV Forums at Roadfly
+ Bentley Forums
+ BMW Forums
+ Cadillac Forums
+ Chevrolet Forums
+ Ferrari Forums
+ Jaguar Forums
+ Lamborghini Forums
+ Lotus Forums
+ Mercedes-Benz Forums
+ Maserati Forums
+ MINI Forums
+ Porsche Forums
+ General Discussion
+ Marketplace Forums
Re: Aux. Fan (Low Speed) help (archive)

[ Follow Ups ] [ 5-series (E34) Message Board ] [ Msg. Board FAQ ]

Posted by gale on July 30, 2001 at 13:46:17:

In Reply to: Aux. Fan (Low Speed) help posted by Ray on July 30, 2001 at 12:19:07:

The low speed circuit is shunted thru a ballast resistor which is mounted on the edge of the fan at about the 4 o'clock position. You can access it thru the kidney grills which come off easily by removing the two clips on top. Follow the leads down to a 3-pin socket down below the bumper. Unplug the socket & measure the resistance across the blue & black wires. It should read in the neighborhood of .5 ohms. The resistor is .5 ohms x 85 watts. You can use four 2 ohm x 25 watt ceramic resistors in parallel to get .5 ohms x 100 watts & save the $34.75 the dealer gets for a new resistor. My old "fried" resistor measured 2.5 k-ohms (basically open) & works fine now with the new resistors. The fan should run continuously on low when the a/c is on & ignition on whether engine is running or not.

If the resistor is ok then check the relay which is in the separate small relay box in front of the left shock tower, ref.:

http://www.nmia.com/~dgnrg/relay1.jpg

http://www.nmia.com/~dgnrg/relay2.jpg

gale
92 735i


Low speed not operating, hi speed ok. Fuses OK! I jumped radiator temperature switch hi speed came on (black/grey to brown). Jumped low speed (violet/grey to brown) low speed wouldn't come on. I could hear relay click but fan did not operate. How do I check further?





Follow Ups:



[ Follow Ups ] [ 5-series (E34) Message Board ] [ Msg. Board FAQ ]
Questions, comments, or problems, please visit the Roadfly help desk.
Roadfly.com Logo © 1997 - 2017 Jump Internet Inc. All rights reserved.