W210 No Air from Climate Control

[UKAltus]

Since getting my E300 back on the road I've been without aircon. Does anyone have a set of fault finding steps for this unit?

I've checked fuses 4 and 7 and both are ok.
I've tried turning the aircon manually to OFF and then restarting the car and moving the blowers back to full position but still no air flow.

Before it stopped working completely the air con wasn't cold but I assumed it was just low gas level and planned to get it refilled. However now its not working at all. Previously it would come on and shut off every couple of seconds and not actually run at full power for more than 1-2 secs before shutting down for 10-15 secs then running at full power for 1-2 secs again and repeating the whole routine.

Would be grateful if someone has diagnosis steps for getting the to the bottom of the problem as to whether its just the low coolant thats caused the system to shut down. Or if I need to look at doing the blower regulator workaround or if its the blower itself? Or duovalve?

Thanks

Justin

 

[BlackC55]

It is normally either the blower motor or the regualtor. Check for 12V at the motor (under the passenger dash panel) when the switch is on full firstly

 

[UKAltus]

Ok so I've got the blower assembly out of the car and thought I'd check the bushes first as its too dark to do much with in the car tonight.

However I'm not sure how to get the black fan enclosure off the blower spindle? Is it just a case of brute force and ignorance? Or is there a knack to it?

 

[UKAltus]

Actually lots of wiggling and heating the rubber up with a hair dryer seems to have done the trick. Although the bushes dont look too bad. Will give it a spray with contact cleaner then have to check the feed to and from the regulator in the morning.

 

[UKAltus]

The blower regulator has part number 011018536 on it. Does this mean its the new type of regulator that can be purchased individually or is it the type that can be replaced by the W140 module?

 

[UKAltus]

Ok so checked for 12v at the feed to regulator and I'm getting 0 even though the blowers are set to full on climate control.

Diagnostic ID 10 shows 6 at full power.

Where to check next?

 

[UKAltus]

Doh. Faulty lead on the multimeter was the cause of 0 reading. Borrowed neighbours and I am getting 12V to the regulator. But from the regulator I'm only getting 0.1V so I assume it means the regulator is at fault

 

[UKAltus]

Thanks it was the regulator at fault. New one purchased for £32 from ebay (my car already had the W140 regulator so it looks like its failed in the past at some point).

My local dealer wanted £250 for the same part.... ouch.