Volvo AWD 850 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 1/2024 850 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

Heater Fan Issue? Strange Sound 850 1997

posted by  Highmile_volvo on  Mon Feb 28 19:49 CST 2011
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Mon Sep 8 20:17 CST 2014
[RELATED]

Hi,

My heater fan seems to be making a strange sound although it doesn't sound like a typical bearing issue like I've heard on my 1979 240. Anyway, it's kind of a low hum sound, like if you had an old radio at the beach and you are trying to tune in a radio station but you only get that buzz/hum sound. The funny thing is it will show up, or get louder when you come to a stop. If you turn the fan up high or low, you really don't hear it, but it's definitely noticeable at medium fan speed. If you turn the fan off, the sound fades a way. does this sound like bearing in the motor or something else?

I need to replace one of the glass headlight lenses for the first time. Is this a fairly straight forward, easy task?

Thank you,

Michael








  •   REPLY TO THIS MESSAGE    EDIT   PRINT   SAVE 

    posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

    If you don't find anything rubbing on the blower then it's probably the motor brushes. As they wear the brush wire runs out of slack and they start loosing contact with the amature. It's a very easy task to take the motor apart once you get the assembly out. Remove the connector adapter and the one screw on the end of the housing. Pull the motor out and with a little bit of solder iron work you can creat some additional brush wire slack and improve the contact. Also oil the bushings while you're at it.



    Mark this post as an answer to my question<- Use this feature to mark quality replies to your post.





  •   REPLY TO THIS MESSAGE    EDIT   PRINT   SAVE 

    posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

    I would investigate the blower being dirty. Have you removed the cover and replaced the filter lately? Any leaves or twigs?

    The hard part of replacing the lense is removing the outside bolt on the back of the headlamp housing. Not much room to get a 10mm socket in there. Once the bolts are out, pull back the headlight housing. You did push down the plastic tab and remove the turn signal first?

    Klaus
    --
    Always willing to listen, just not able to take direction.



    Mark this post as an answer to my question<- Use this feature to mark quality replies to your post.





    •   REPLY TO THIS MESSAGE    EDIT   PRINT   SAVE 

      posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

      Hi

      Those sounds from the heater fan have gone away. There is still s slight, slight hum, a different sound that I noticed the other day. But the main sound that had me concerned is gone. So, it if was some sort of dirt or debris in the fan, it may have blown itself out.

      You mentioned, "Have you removed the cover and replaced the filter lately". I haven't checked the in-cabin air filter. It's been replaced a couple of times, once when I first bought the car at approx 84k, then at the next major service. So, not sure if it's due to be replaced yet or not. I should check it incase it has become dirty or clogged with something.

      In regards to the headlight lens, I haven't done anything with that yet.

      Michael


      Mark this post as an answer to my question<- Use this feature to mark quality replies to your post.





      •   REPLY TO THIS MESSAGE    EDIT   PRINT   SAVE 

        posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

        I suggest you at least remove the 2 torx screws and look at the filter. It usually gets dirty in one year of operation.

        The noise could be brush/temperature related. The colder the plastic gets, the more noise a light touch will make.

        Headlights are more important.

        Klaus
        --
        Always willing to listen, just not able to take direction.



        Mark this post as an answer to my question<- Use this feature to mark quality replies to your post.




<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.