Cabin heater blower

[Rhys25]

Hi, new to forums so go easy please
I have an E220 convertible, 2013 (A207) and the cabin heater blower is playing up.
To start with it stopped working completely, so I replaced the blower/fan under the dash.
It worked briefly but since then it reaches full power to clear the windscreen, then shuts down. After a short while it does the same again.
I’ve replaced the regulator and checked the fuses but the problem persists.

This issue has coincided with the Auxiliary Battery Malfunction message popping up, I haven’t done anything about that as our local merc specialist said he can’t find anything wrong with it.

My guess is the two are linked and my mechanic was having an off day, any thoughts?

 

[mioba]

Did your mechanic scan for fault codes?

 

[Rhys25]

He did, said nothing came up, even though the message comes up on the dash every day.

 

[mioba]

What scanner is your mechanic using.

It must be really crap or non existent to not show a fault that is on the screen.

The reason I ask, is because reading on what you have replaced is indicative of playing parts darts, which is a huge waste of money.

 

[Rhys25]

No idea, sorry not helpful.
Maybe time to find a new mechanic, just hoping to avoid the diagnosis fee, but if that would pinpoint the issue would obviously be better than my dodgy darts!

 

[mioba]

Where are you located someone may have a recommendation for you.

Post back how you get on

 

[Rhys25]

Lancashire, Blackburn/Burnley/Preston

 

[peterws1957]

Lancashire, Blackburn/Burnley/Preston

There is CVM (Preston) who are an MB indie in Fulwood. I've never used them but others have with good results. If you're willing to travel a bit further there is Blackpool Automotive also MB only who I've found to be very good.

 

[Rhys25]

There is CVM (Preston) who are an MB indie in Fulwood. I've never used them but others have with good results. If you're willing to travel a bit further there is Blackpool Automotive also MB only who I've found to be very good.

Thank you, I’ll give CVM a go.
In the meantime, with the help of my stupid approach of randomly changing parts, I’ve replaced the auxiliary battery. Problem persists
Having got the multimeter on the auxiliary battery, I notice that the voltage remains constant at 12.6V, both with engine off and when running with as much electrical load as I can muster (heated seats, rear demist, neck blowers, etc)
Is there some kind of relay in the system to engage the auxiliary battery when required?

 

[mioba]

Stop chucking money at non existent faults. Let it be with a good garage.