95 855 turbo blower motor

VoguishSpace272 · Post by **VoguishSpace272** » 19 Aug 2024, 18:39

I'm trying to diagnose the reason why the blower motor won't start, as far as I can tell from the schematics the red wire to the blower motor itself should have power when the key is on. However, that is not the case, all the fuses and relays for the blower motor are working and the power stage is new (same as the blower motor). what could prevent the motor from turning on?

Post by **scot850** » 19 Aug 2024, 19:29

Do you have any flashing lights on the MCC/ECC unit at all?

Have you tried running the system in manual mode?

Is the system MCC or ECC?

Neil.

VoguishSpace272 · Post by **VoguishSpace272** » 19 Aug 2024, 19:59

i do have flashing light and it is a ECC system

Post by **misha** » 20 Aug 2024, 02:23

Flashing ac & rec lights means that there is a fault(s) stored in ecc unit.

It's probably bad ecc unit...BUT...

You can try to reset it by unplugging it's connectors and wait for about 15min.
Is fuse for blower fan speed 4 ok?

Second thing that can prevent the blower to run are thermistors under the driver's and passengers side grab handles at headliner on the roof.

If the little fans are full of lint and dust and not spinning...the blower will not work.

They should spin for a few seconds when key is in pos.II(test run) and stop untill the blower fan is turned on.
When blower fan is turned on...they should spin all the time along with blower....untill the blower is turned off.

VoguishSpace272 · Post by **VoguishSpace272** » 20 Aug 2024, 11:09

I opened the thermistor on both sides and cleaned them and test with the key in position II, both worked. I pulled the codes off of the obd1 port and the codes are: 211, 231, 323, 414, 419

VoguishSpace272 · Post by **VoguishSpace272** » 20 Aug 2024, 11:32

After clearning the codes the only ones that remain are:
231 - Ventilation damper motor position sensor open circuit or shorted to 12 volts

323 - Ventilation damper motor active too long

419 - Faulty diagnostic signal from blower fan power stage

Post by **scot850** » 20 Aug 2024, 12:28

419 - is the culprit here I would suggest. May be the ECC unit is bad. Try fixing the issue below and reset the ECC as Misha mentioned and check for codes again.

231/323 are I believe the inlet flap above the fan motor. Either the flap servo motor has failed, or more likely the short plastic rod between the flap and motor has broken or become disconnected. I would suggest if your car has not had the modification done of fitting a cabin filter and tray from a 98-00 V/S/C70 there will be a bunch of crap in the area. This can be access by removing the wiper arms and plastic cover tray (you will have to remove the fuse box cover on the driver's side). You can then get a vacuum down and clean the top of the flap. Removing the fan motor to will allow cleaning the lower part easier too.

At last time I checked if the plastic are is broken they were cheap and still available. Otherwise a junkyard. If no luck anywhere else let me know and I'll send you one.

Neil.

Post by **misha** » 20 Aug 2024, 12:50

Are you aware that there are two types of power stages...for mcc & ecc?
The one for ecc is power stage with aluminum coolers...the other one for mcc is a simple resistor.
Is the replacement exactly the same like old one?
They also look different...if they are different.
MCC:
https://www.google.com/search?client=ms ... sid=mosaic

ECC power stage:

Do you have a proper power stage installed?

Post by **scot850** » 20 Aug 2024, 13:32

There were if I recall different part numbers over the years, so please check your replacement is the correct one. If you can't confirm the part number here and we can check for you.

I should also add make sure the servo motor is in the correct position before connecting the connector to the flap.

Neil.