240 General: The mysteries of the blower/heater motor revealed!!

[honestjoe]

Having just replaced my motor over the crimbo and now find myself staring at the old one..I managed to reduce the amount of damage to it by realising fairly quickly that something was not right..(the dreaded aroma of burning insulation)..These pictures here show the motor dismantled and the probable causes of failiure...Remove the two screws holding the motor assy to the plastic star mounting..(no need to remove rubber grommets)...Fan is actually push fit so remove this by resting motor on wooden battons or the like either side of the base of the fan so the motor is vertical and a few inches above the ground..put something soft for the motor to fall onto when fan is released...then using a punch and small hammer hit the central spindle gently and the fan will come off..next remove screw that hold the resistor circuit board..Remove brush holders by unclipping a single spring that holds the brush secure to thier seats..once spring is removed the brush holders will be free..(They are also soldered to the resistor board)..now remove the coil..This is secured by two pins wedged down the sides of the coil and bent over at the ends..Straighten the ends and knock out with light tapping and a suitable nail or thin punch..you will see them in one picture..they look like floorboard nails..Now all you should have left is the armature and bearing carriage..to remove motor from this frame you have to ping off the bearing retaining clips either end with a small flat blade screwdriver..(put a cloth over these when you do this they will fly!)..Putting them back on will be another story!..now you can remove the armature and inspect the bushes/bearings..The one fan end was very sloppy indeed causing the armature to bind on the coil..also one picture shows the comutator with carbon deposits bridging the segments in the gaps between each..clean this out with a fine blade.These deposits will cause a short.I have also in the past cleaned the comutator with lighter fuel and a soft rag..(tailgate wiper motor)That is all i can think of at the moment..but i am going to try and rejuvinate this unit if i can by replacing the bushes (if i can still get them?)..it just a project but i cant help tinkering and although returning an ancient motor which has already had a life to a heater matrix may be foolish or risky..But hey!..i"ve got to know and maybe someone somewhere in the outer reaches may find this useful...I"ve got to go to work now..a few more pictures to follow later..cheers hj.

[honestjoe]

A few more pictures..These show the bridging on the comutator segments and the severe wear to one bushing in particular

[marcmarel]

BTDT. The motor is made by Electrolux, you might find another bushing in an old vacuumcleaner. Maybe the household appliance store?

A better and safer source is another failed 240 or 140 blower motor, it's always just the one that goes bad (on the left).

[honestjoe]

Thanks marcmarel..I did a google search for electrolux bushings without much success..I need some bearings for my petrol hedgetrimmer and was going to try our local BSL..Cheers hj.

[chesters6]

lots of bearings on ebay ,now you have the originals to measure you should find some

[marcmarel]

I think Electrolux uses a sintered bronze bearing, like this: http://www.aptsbearing.com/bronze.html You could look for ballbearings to replace it.
I was going to try that but found an old blower motor to scavenge the bearing from.

There is also a Bosch (IIRC) version of the same blower motor, which has ball bearings. Should last even more for ever than the bronze.

[honestjoe]

Thanks for the replies chaps..I did cross my tiny mind to use ball bearings but would they really last as long as bushes?..The advantage of brass or bronze is that they dont actualy need lube..perhaps rubber cased anti dust ball bearings may work?..I mean those original bushes lasted at least twenty four years..thats pretty good going for any bearing..very hot in the winter and dusty in the summer?..it would be interesting to see the operation with bearings though..cheers hj.

[Honest989]

Originally Posted by honestjoe

Having just replaced my motor over the crimbo and now find myself staring at the old one..I managed to reduce the amount of damage to it by realising fairly quickly that something was not right..(the dreaded aroma of burning insulation)..These pictures here show the motor dismantled and the probable causes of failiure...Remove the two screws holding the motor assy to the plastic star mounting..(no need to remove rubber grommets)...Fan is actually push fit so remove this by resting motor on wooden battons or the like either side of the base of the fan so the motor is vertical and a few inches above the ground..put something soft for the motor to fall onto when fan is released...then using a punch and small hammer hit the central spindle gently and the fan will come off..next remove screw that hold the resistor circuit board..Remove brush holders by unclipping a single spring that holds the brush secure to thier seats..once spring is removed the brush holders will be free..(They are also soldered to the resistor board)..now remove the coil..This is secured by two pins wedged down the sides of the coil and bent over at the ends..Straighten the ends and knock out with light tapping and a suitable nail or thin punch..you will see them in one picture..they look like floorboard nails..Now all you should have left is the armature and bearing carriage..to remove motor from this frame you have to ping off the bearing retaining clips either end with a small flat blade screwdriver..(put a cloth over these when you do this they will fly!)..Putting them back on will be another story!..now you can remove the armature and inspect the bushes/bearings..The one fan end was very sloppy indeed causing the armature to bind on the coil..also one picture shows the comutator with carbon deposits bridging the segments in the gaps between each..clean this out with a fine blade.These deposits will cause a short.I have also in the past cleaned the comutator with lighter fuel and a soft rag..(tailgate wiper motor)That is all i can think of at the moment..but i am going to try and rejuvinate this unit if i can by replacing the bushes (if i can still get them?)..it just a project but i cant help tinkering and although returning an ancient motor which has already had a life to a heater matrix may be foolish or risky..But hey!..i"ve got to know and maybe someone somewhere in the outer reaches may find this useful...I"ve got to go to work now..a few more pictures to follow later..cheers hj.

I've found an old post of yours about your heater blower not working.

In recent months my fan was making squealing noises. It would be ok if you went up a level of speed and then brought it back down. Now settings 1&2 produce the smell of burning insulation and 3 still works.
Diagnosis? Resistor is borked and the fan is probably not operating at 100 %.

I searched the internet and found some really useful articles but then later determined that (a) they were all american and (b) they were of the combined unit type.

The type you and I have, assuming you're english (or just not canadian or american) is the standard unit.

Do you have any advice on how to replace the fan (I assume the resistor is integrated to that fan) because from what I've researched, I think I need to remove the dash board basically to get the whole unit out, take it apart and replace the fan before putting the whole thing back in again.

It'd be nice to see if there was an easier way of doing it!!

[twoluckyone]

In this link to the Dutch volvo 240 forum you will find a lot of info.
There are also links to english pages in that thread:

http://volvolvo.nl/threads/10696-kac...=kachel+ratelt

[honestjoe]

Sorry for your troubles..especially with this weather,its no fun with no heater..I did this job a while back and if you click on my avatar and go into my statistics and all threads started by myself you will find one that starts with the word..typical..and that should give an idea of whats involved..Strangely my pictures did not load but maybe its just my computer settings?.. i"m sure you would find it useful..There are a lot of experienced folk here to help you..hj.