Heater fan problems

[SJ]

The problem can be worn brushes on the fan motor.
If the controller is set to some position, like Economy, the fan seems to
have a life of its one. Sometimes it works, sometimes it dont. It might stop
when going over a bump, then start again over the next bump. The fan might
work fine when you stop the engine, and refuse to work when you start up.
These are symptoms of worn brushes which provide only intermittant contact
at the commutator. Vibrations and temperature changes have an effect on the
brush positions.

You need to remove the blower motor to replace the brushes.
You will find the commutator with a deep groove in it . .wear marks from the
brushes.
I'm not sure if it pays to just replace the brushes. Unless you can cut the
commutator to remove that wear groove. A local alternator repair shop might
cut them for you on a lathe for couple bucks. I  havent tried that.

Huw may have some tricks up his sleeve. Maybe you can file the brushes to
fit the worn grooves. Using the old brushes as a pattern.

Getting at the blower motor is not an easy job. It's a royal pain. Getting
the sealing gasket to release was the biggest problem as I recall. Very
little clearance to get your hands down there.

For that much pain, I prefer to put in a new blower motor.I think I paid $90
for a new motor - that was 2 years ago.

While we are on the subject, maybe someone can refresh my memory and tell me
why some of the console has to be taken apart in order to remove the blower
assembly in the engine compartment.
As I recall, there was no mechanical connection between the blower motor
assembly and anything on the other side of the bulkhead.

SJ
85 Dodge PU, D-250, 318, auto
85 Audi 4k - - sold but still on the road
88 Audi 5kq
90 Audi 100q


> Message: 7
> Date: Sun, 26 Dec 2004 17:32:44 -0700
> From: Zsolt <zsolt1 at telusplanet.net>
> Subject: Heater fan problems
> To: <quattro at audifans.com>
> Message-ID: <6.0.1.1.2.20041226172431.02866d40 at pop.telus.net>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> My heater fan has started acting up recently. It is also pretty cold right
> now, so it's not pleasant. The car is an '88 5ktq, and the symptoms as
follow:
>
> - the fan seem to come on by itself in ECO mode when the car is first
> started up
> - in DEFROST mode it doesn't start until it starts blowing by itself (it
> used to start blowing immediately when it's pressed even cold engine)
> - when the engine is re-started, the fan doesn't come on for a looooong
> time, or at all.
>
> I am guessing it's the digital controller unit. Any BTDT?
>
> Thanks, and Happy Holidays everybody!
> ZSolt