GRRR..Interior heater blower intermittent

lordofthenazgul

Active Member
Joined
Jan 5, 2004
Messages
62
Location
NW England
Car
C240 ESPRIT, 1998
Grr.....My interior blower motor is operating intermittently which isnt very nice when its about -10 outside and you cant see where you are going.

It'll come on and blow air round for varying times between 5 secs and 5 mins, then stop working for anything between 2 mins and about 3 days!...
When it DOES operate it goes at the speed the switch is set to on the heater control module so it is getting the correct voltage to the fan, it just seems to go on strike more often than a french docker.
Voltages at the motor check out... 3 pins, one @ +12v, one at earth and the other switching from 0 - c7.5v depending on blower switch position.

Local dealer reckons it is the motor speed regulator, a unit which bolts onto the motor which looks like a sort of diode pack.

Anyone shed any light on this before I take it to the dealer & hand over about £200 in desperation to get it sorted??

PS heater control module replaced in Oct, car has A/C
 

zanyaminal

New Member
Joined
Feb 7, 2004
Messages
9
Heater fan

Having exactly the same problem with my C250TD. I changed the fan about a year ago which cured the problem but as soon as the cold weather came in it started again and now it's given up the ghost completely. Being an electrician myself I have already considered the speed regulator which I think, like you said, is a bank of resistors or diodes. It may be worth replacing yourself as it is easy to do and a lot cheaper than those robbing gits at the dealership. Just unscrew the panel in the passenger foot well below the glovebox and the fan and diode pack are sat in there held in with four screws. Will give it a go and keep you posted on the results.
 

jimmy

MB Enthusiast
Joined
Aug 8, 2002
Messages
2,316
Location
Northamptonshire
Car
Discovery 3 TDV6, Discovery 300TDi - Plaything!
I had a similar problem except my fan would sometimes not start but once started it was OK. I used to have to thump the underneath of the passenger dash to get it started.

A new motor under warranty sorted it and it is now fine.
 

Kinky

MB Enthusiast
Joined
Apr 23, 2003
Messages
1,316
Location
Berkshire
Hummmm ..... I've got a similiarish problem !

With A/C off it won't blow hot air (unlike me) - but when I turn on the internal air circ button - I blows away nice and hot.

Same with the air con (I think). Basically won't blow hot air unless as above.

K
 

GRAV888

MB Enthusiast
Joined
Mar 5, 2003
Messages
6,324
Location
Rochester and Lancashire
Car
2017 CLA 180 AMG in Black (mine) 2018 GLA 200 SE in Black (wifes)
Shude said:
I just searched for "blower motor" and do you know what I found?

HOWTO: Blower motor / ventilation fan removal on w202 (lots of pics)

Some kind soul already wrote a HOWTO for it! ;)
3 cheers for the Shudemeister :bannana: :bannana: :bannana:
(Well bananas actually)

I had the same problem last year as well and it turned out to be the motor.
It was only about £50 from the stealers.
Easy DIY job with the "how to" ;)
 

zanyaminal

New Member
Joined
Feb 7, 2004
Messages
9
I've discovered a dodgy connection on plug that connects the speed regulator (diode pack thingy!) to the blower motor. I've sent you a pvt msg lordofthenazgul, just hope you get it before you throw your money down the drain at the dealership.
 

Shude

Hardcore MB Enthusiast
Joined
Jun 1, 2002
Messages
13,882
Location
Cheshire
Car
CLK55 AMG
GRAV888 said:
I had the same problem last year as well and it turned out to be the motor.
It was only about £50 from the stealers.
Easy DIY job with the "how to" ;)
I got a price for the motor from my parts dept, it was £150 plus VAT, and that was with a small discount! The breakers wanted £80 for a 5 year old used one! No idea how you got one for £50.

My repair was free anyway, all it took was some motor TLC :)
 

Shude

Hardcore MB Enthusiast
Joined
Jun 1, 2002
Messages
13,882
Location
Cheshire
Car
CLK55 AMG
My fan has just started going irregular! It's dead 90% of the time, then when someone slams a car door or I go over a bump it starts up again. Worst time of year for this to happen, because the car mists up very quickly without the heater and I can't see out of the car to drive! :(

Time to read my own instructions and examine the motor and connections again I think!
 

zanyaminal

New Member
Joined
Feb 7, 2004
Messages
9
Shude said:
My fan has just started going irregular! It's dead 90% of the time, then when someone slams a car door or I go over a bump it starts up again. Worst time of year for this to happen, because the car mists up very quickly without the heater and I can't see out of the car to drive! :(

Time to read my own instructions and examine the motor and connections again I think!
Read my previous replies Shude. Sounds to me that this dodgy connector is a common problem.
 

Shude

Hardcore MB Enthusiast
Joined
Jun 1, 2002
Messages
13,882
Location
Cheshire
Car
CLK55 AMG
zanyaminal said:
Read my previous replies Shude. Sounds to me that this dodgy connector is a common problem.
I read your replies, that's why I'm going to strip the underside of the dash and take a look at the connectors! :) I'm hoping it's just a connector and I can get it working again, it's way too cold to have no ventilation in the car. The heater actually works fine though, if I get up to about 70mph+ the sheer force of the air going into the car means it gets through the heater core and the various filters etc and eventually into the car, over the windows to slowly de-mist them, so motorway driving isn't bad, pull off the motorway however and it's condensation-city again! :(
 

Shude

Hardcore MB Enthusiast
Joined
Jun 1, 2002
Messages
13,882
Location
Cheshire
Car
CLK55 AMG
zanyaminal said:
Good luck Shude. Let us know the outcome.
I am now 99% sure it's the connector, I took the dash pieces away and got to the motor and the connector is loose! When correctly seated it's fine, but because it's a loose fit the slightest knock and it falls out! :( . Luckily the connector can be detached by itself (no need to remove fan and controller then!) so I can bring it inside the house where it's warm to "adjust" it :) .

This is the connector I'm talking about:



Given the shape of it, I might just wrap some electrical tape around it so it's a tighter fit.
 

zanyaminal

New Member
Joined
Feb 7, 2004
Messages
9
Thats the connector!!! Mine was loose aswell. I think it's the actual spade connections inside the plug. I removed the wires by sticking a watchmakers screwdriver down the end to release the connections and tweaked them up with a pair of pliers. This seems to have done the trick but if it happens again I'll purchase a new one, it's only two wires with a plug at one end and spades at the other.
This is obviously a very common problem which i'm sure MB are aware of so why do the robbing gits insist it's the fan or speed regulator that's at fault and rip people off???? :mad: :mad: :mad:
 

Shude

Hardcore MB Enthusiast
Joined
Jun 1, 2002
Messages
13,882
Location
Cheshire
Car
CLK55 AMG
GRR! Bloomin' connector is stupid!

I took it off, squeezed the little connectors so they were a tighter fit, and pushed it back in place. Stood back, whizzed the dial up to the top and... nothing happened.

I tapped the bottom of the fan with my maglite and it fired into life, but gradually got slower. I pulled on the connector and it got faster, and faster, and faster. After a few seconds it was at full speed, with me still pulling the wire down pretty hard. Let go, fan slows to a stop!!

I am going to take it all out again and see if I can make up my own wires/connectors for it! It's just stupid the way it is now, and VERY frustrating!
 

kevinE200

Member
Joined
Jan 30, 2004
Messages
36
I am driving a 98 E200 and I don't have this problem ..yet!
But I want to share my experience with you that I had the same problem when I was driving a Jaguar XJ. The reason was the worn out carbon brushes and it just couldn't touch the spining core and there was no current to fire the motor. When I pull the wire, it moves. When I release the wire, it stops. Someone said that those carbon brushes can be changed in the machine shop but I just purchased another new one instead.
Hope this help.
 

Shude

Hardcore MB Enthusiast
Joined
Jun 1, 2002
Messages
13,882
Location
Cheshire
Car
CLK55 AMG
kevinE200 said:
I am driving a 98 E200 and I don't have this problem ..yet!
But I want to share my experience with you that I had the same problem when I was driving a Jaguar XJ. The reason was the worn out carbon brushes and it just couldn't touch the spining core and there was no current to fire the motor. When I pull the wire, it moves. When I release the wire, it stops. Someone said that those carbon brushes can be changed in the machine shop but I just purchased another new one instead.
Hope this help.
Hmm, that's very interesting! I might take the motor out and have another look at it. A new motor is £150+ so I don't really want to buy a new one, second hand is still about £70-80 from a breaker, and that will be out of a car of similar age I imagine so could fail at any time! :(
 

Bladerunner

New Member
Joined
Oct 5, 2003
Messages
6
Location
Tamworth,Staffs
Car
C200
Interesting reading, I have very similar problem - intermittent blower speed and an intermittent squealing sound. bl**dy annoying. Have had the motor out 2 or 3 times, tried cleaning the brushes etc but to no avail. I wonder now if my connector is loose, or do I need a new motor ?
I will be interested to hear the outcome Shude.
I also have an intermittent fuel gauge - a well documented / common fault as well by the sound of it.
Nice car apart from these niggles though. C200 Classic, '98, 60K. :confused:
 

jimmy

MB Enthusiast
Joined
Aug 8, 2002
Messages
2,316
Location
Northamptonshire
Car
Discovery 3 TDV6, Discovery 300TDi - Plaything!
I tried to get new brushes for mine, was told you cannot get them. I contacted the motor manufacturer, Valeo direct through work and they do not sell the brushes seperately. I have a box of brushes for motors, starters, alternators etc and none were a suitable size. I was fortunate enough to be able to claim on my AA warranty, the labour charge was very high for changing that motor!!
 

Shude

Hardcore MB Enthusiast
Joined
Jun 1, 2002
Messages
13,882
Location
Cheshire
Car
CLK55 AMG
Bladerunner said:
I will be interested to hear the outcome Shude.
It's still dead! I tried messing around with the connectors but it only made it worse, next step is to take the motor out from under the dashboard and try the connectors when I can actually see them! They are just normal, crimped spade-type connectors so I might try making my own little piece of wiring up to replace the factory one, if it really is the connector (which I think it is).

I will document the outcome!
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top Bottom