muddy
10-11-2009, 01:26 AM
Neither the fan behind the glove box nor the auxilliary rad fan worked on the '99 Passat just purchased. No surprise at all given the age of the car.
Removing the dash fan (Climatronic) was easy - once you ignored the Haynes manual.
Disconnect battery negative lead.
Prise out light unit within glovebox and unplug wiring.
Remove 7 screws that hold in the glove box assembly.
Remove the four 10mm bolts (visible when you look up from directly under the dash - not recommended if you have a bad back! - use a mirror instead) that hold the two end brackets for the airbag and move the assembly a few inches towards the centre of the car and it will lodge in place without putting any strain on the airbag connection.
Unplug two wiring spade connectors. Remove shiny Phillips screws and lift out fan assembly. Masses of room.
Rotate electrical connector so that lugs line up with slots.
Press each of the three natty rubber 'lugs' down in turn and pull motor out slightly at each one.
End plate comes off to reveal two worn out brushes. Unsolder wires and remove.
Clean slightly blackened commutator.
Buy two new brushes (staggered to see someone on eBay charging £12.50 .....) - or do as I did, cut down some Lucas dynamo brushes to correct dimensions.
They are soft and will sand down to size very easily.
Because the brush holders are offset from the centre line, the brushes wear to a distinctive curved shape. You need to file/sand the new brushes to a similar profile so that they bed in easily.
Wrap a bit of fine sandpaper around a socket with the same diameter as the commutator to get the shape correct.
Fit brushes and solder wire braid into place of course.
"Reassembly is the reverse of dismantling."
The rad fan is a bit more complicated.
Unplug wiring under black cover on power steering reservoir. (Brown plus black/red wire in light brown snap connector)
Remove air intake duct (two screws on front ledge) and elbow to air filter box. Remove headlight wiring plug, pressing spring clip in and wiggling off.
This gives ample space to remove fan (I think Haynes suggest radiator removal .....).
Remove wiring from two or three springy plastic clips along bottom of rad.
Unscrew/remove one short Phillips screw by top fan lug.
Fan housing rotates clockwise to disengage three lugs but you may have to push the projecting plastic 'lever' on the bottom mounting to release a 'locking' pip.
Remove fan assembly through space created.
Undo 3x 10mm bolts to remove shroud.
Unclip plastic wiring holder and cut tiewrap to remove wire from shroud.
Undo 8mm nut that is LEFT HAND THREAD, fan blade just lifts off.
Now the tricky part:-
End plate is 'staked' to motor casing by 8 lugs that come through slots and are pressed apart at the factory to lock the plate on. Squeeze lugs together - or tap lugs back together with small round punch.
Lift off plate (with bronze end bush so put in a drop of oil to be soaking into bearing)
Discover four worn out carbon brushes.
Clean commutator.
Make four new brushes from cutting down two more sets of Lucas Dynamo brushes. Solder new wires back to original locations.
Reassemble.
The now-upstanding lugs can be tapped back sideways, again using a small punch, until the endplate is firmly relocated.
Reassemble and refit.
Edited to add:-
When I tried to do this same job on my '98 1.8T last year - I found a different design of brushholder with 'hairpin' rather than coil springs. The brushes had worn completely away and the springs had then chewed up the copper commutator. So that one was scrap.
The '99 one with coil springs reached a point of wear such that the braided copper wire was at bottom of a slot and stopped the brush being worn away to nothing. At that point the contact is lost, fan stops working but commutator remains serviceable.
A much better design.
Removing the dash fan (Climatronic) was easy - once you ignored the Haynes manual.
Disconnect battery negative lead.
Prise out light unit within glovebox and unplug wiring.
Remove 7 screws that hold in the glove box assembly.
Remove the four 10mm bolts (visible when you look up from directly under the dash - not recommended if you have a bad back! - use a mirror instead) that hold the two end brackets for the airbag and move the assembly a few inches towards the centre of the car and it will lodge in place without putting any strain on the airbag connection.
Unplug two wiring spade connectors. Remove shiny Phillips screws and lift out fan assembly. Masses of room.
Rotate electrical connector so that lugs line up with slots.
Press each of the three natty rubber 'lugs' down in turn and pull motor out slightly at each one.
End plate comes off to reveal two worn out brushes. Unsolder wires and remove.
Clean slightly blackened commutator.
Buy two new brushes (staggered to see someone on eBay charging £12.50 .....) - or do as I did, cut down some Lucas dynamo brushes to correct dimensions.
They are soft and will sand down to size very easily.
Because the brush holders are offset from the centre line, the brushes wear to a distinctive curved shape. You need to file/sand the new brushes to a similar profile so that they bed in easily.
Wrap a bit of fine sandpaper around a socket with the same diameter as the commutator to get the shape correct.
Fit brushes and solder wire braid into place of course.
"Reassembly is the reverse of dismantling."
The rad fan is a bit more complicated.
Unplug wiring under black cover on power steering reservoir. (Brown plus black/red wire in light brown snap connector)
Remove air intake duct (two screws on front ledge) and elbow to air filter box. Remove headlight wiring plug, pressing spring clip in and wiggling off.
This gives ample space to remove fan (I think Haynes suggest radiator removal .....).
Remove wiring from two or three springy plastic clips along bottom of rad.
Unscrew/remove one short Phillips screw by top fan lug.
Fan housing rotates clockwise to disengage three lugs but you may have to push the projecting plastic 'lever' on the bottom mounting to release a 'locking' pip.
Remove fan assembly through space created.
Undo 3x 10mm bolts to remove shroud.
Unclip plastic wiring holder and cut tiewrap to remove wire from shroud.
Undo 8mm nut that is LEFT HAND THREAD, fan blade just lifts off.
Now the tricky part:-
End plate is 'staked' to motor casing by 8 lugs that come through slots and are pressed apart at the factory to lock the plate on. Squeeze lugs together - or tap lugs back together with small round punch.
Lift off plate (with bronze end bush so put in a drop of oil to be soaking into bearing)
Discover four worn out carbon brushes.
Clean commutator.
Make four new brushes from cutting down two more sets of Lucas Dynamo brushes. Solder new wires back to original locations.
Reassemble.
The now-upstanding lugs can be tapped back sideways, again using a small punch, until the endplate is firmly relocated.
Reassemble and refit.
Edited to add:-
When I tried to do this same job on my '98 1.8T last year - I found a different design of brushholder with 'hairpin' rather than coil springs. The brushes had worn completely away and the springs had then chewed up the copper commutator. So that one was scrap.
The '99 one with coil springs reached a point of wear such that the braided copper wire was at bottom of a slot and stopped the brush being worn away to nothing. At that point the contact is lost, fan stops working but commutator remains serviceable.
A much better design.