UrS4 Heater Fan Motor Replacement

[Fred Munro]

My squeaky heater fan is a thing of the past (I hope) - I just replaced
the blower motor& fan yesterday.
    I followed Gary Martin's procedure as forwarded by Dwayne and it worked
OK. The box does not have to come out and the coolant does not have to be
drained.
    The job took 6.5 hours - about 2 hours to remove and replace the screw
at the bottom of the air intake housing ( now that job is a test of
patience), 1/2 hour to fabricate a tool  to lift the box, and four hours for
the main stuff. The hardest part of the procedure was the air intake bottom
screw, followed by replacing the rubber bellows connecting the A/C box to
the heater box. Judging by the amount of skin I lost, there are lots of
sharp edges in there.
    It is not possible to get the fan motor out without lifting the box -
believe me, I tried. As Gary mentions, the box must be lifted about 4 inches
at the front to get the fan out. I was concerned that the defrost vents or
the bellows connecting the box to the rear heater ducts might come off when
the box was lifted, but all appears OK. It looks like you really don't want
to have to pull the centre console.
    Since the gasket is not replaced in this procedure, the box is no longer
stuck to the firewall, but it may reseal with time.It wiggled around a bit
after I initially clamped it down, but it was solid by the time I had
everything buttoned up.
    Gary's procedure is attached for all those with squeaky motors - judging
from the comments on the list, this is a common problem.
    The brushes and commutator on the old motor show little wear - Bosch
seems to have fixed the brush wear issue, now they just need to work on
their bearings.

Fred Munro
'94 S4 118k km

> ---------- Forwarded message ----------
> Date: Thu, 28 Oct 1999 22:23:13 -0400
> From: "Martin, Gary G" <MartinGG at aetna.com>
> To: AUDI S Cars Discussion List <audi-s-cars at lists.boldfish.com>
> Subject: VENTILATION BLOWER REPLACEMENT
>
> Finally replaced my intermittently squealing AC/heater fan this week and
> maybe what I learned will be of help to someone else.
> If you are using the Bentley procedure, there are several things you DO
NOT
> have to do.
> You,
> DO NOT have to remove the blower box.
> DO NOT have to remove any interior trim, ie. center console, like I did.
> PITA to get back in, for me at least.
> DO NOT have to remove coolant lines to heater core.
>
> Credit has to be given to a procedure I found on the Q list, modified
> somewhat.
>
> Here we go.
>
> Inside car: Remove one bolt each side, which attaches footwell airflow
piece
> to center blower box. Near center console on both sides.
> Outside car. Remove wipers, motor and assembly and 3 covers over A/C and
> blower box and controls.
> Remove vacuum hoses and electrical connections that will get in the way of
> lifting the blower box about 3-4 inches.
> Remove hold down strap on top of blower box.
> Remove large rubber  connector between blower box and evaporator box.(Hose
> clamp on left side, slip over lip on blower box).
>
> Now you have to break the box loose from its seal. Unless you are feeling
> really strong, I think you will need mechanical help.
> There is a boss on the front of the box to attach a puller to. I made a
> puller out of a  2x4 inch piece of metal, bent
> into a hook at one end, and 90degree angle at other end, put two 6"
threaded
> rods thru it about an inch apart, attached
> another piece of metal at the other end. Put a peice of 2x4 on the strut
> brace, and used a pry bar to lift up on my hook.
> No problem.
> Remove housing on blower box that  rubber connector was slipped onto. Two
> screws  visible on the top, and
> one on the bottom.  This is a touchy/feely one, but you can get it out,
and
> in. (I did). Worst case, it could be broken,
> as Q list proc said, and this part of housing attached here with contact
> cement or something. Here is where the motor will come out.
>
> Almost there. Motor is held in with a snap ring on the right end. Take
that
> off and the washer. Lift, pull and maybe a curse
> or two, and you can get the blower out of the box.
>
> Inside the blower box, there are 3 rubber bumpers, which support the
motor.
> These need to be lubricated with petroleum jelly(veener schlipper).
> In fact, I'm thinkin these little dry bumpers may have been the cause of
the
> squealing.
> Put new motor in. Line up guide lip on end of motor with housing slot and
> make sure bumpers stay in place.
> note: I used a magnetic tool to hold the screw for the bottom of the
> housing, to get it started.
> Don't forget to attach ALL the connections. Not like I did, when I fould
the
> wipers wouldn't work. I took a break after that!
> Good luck. HTH......Gary 94UrS4......nice and quiet again.