Blower problems for CLK 320 W208

[FOGWAR]

Hello all,

As the title states I'm having problems with the blower control on my 99 - 320 CLK. The blowers only work intermittently, I have to turn it right up on to full then back off a few times to get it working. Is it the blower motor that needs replacing or an I looking at something a little less costly ?

Any help would be greatly appreciated

 

[daveenty]

Had this on mine and it turned out to be a relay (located under the glove box passenger side)

Depends on the price of a blower motor, but the item on mine cost about £140.00 (plus about an hour to fit) though I got it done under warranty.

Mine was working when it wanted, occasionally go for ages, then not go at all. Seemed irrespective of where the switch was set, just worked when it wanted to and for limited periods of time.

Any good Indie could check it out for you to confirm.

 

[television]

Its more normal on an intermitant fault to be the control unit rather than the fan
this is the norm in servicing and repairs, though there is always the odd one out.
As with Daveenty answer, tapping the relay could show up the fault,on intermitant relays the fault is always a dry joint on the PCB or dirty relay contact.

Malcolm

 

[FOGWAR]

Thanks for the responses fellas.

It's literally just started this morning (worked absolutely fine up until this moment). I'll get looking at this relay problem and see what I find, do you have to remove the glove box?

I've also read that it can be the brushes on the motor, can these be purchased and replaced without too much diy expertise?

Cheers.

 

[television]

Thanks for the responses fellas.

It's literally just started this morning (worked absolutely fine up until this moment). I'll get looking at this relay problem and see what I find, do you have to remove the glove box?

I've also read that it can be the brushes on the motor, can these be purchased and replaced without too much diy expertise?

Cheers.

If it is the brushes, no you cant buy them, you go to say a garden machine service center and get the nearest size to it bigger, you can file it or use sandpaper, radius all four corners, there are theads on doing it here.

Malcolm

 

[daveenty]

you can file it or use sandpaper, radius all four corners

Good grief.....takes me back to the old Ford Cortina days......*How Much???*

Not buying them mate, make my own


D'ya know, if anything I've got worse over the years

(The Cortina was the Mk 1, of which I've had loads....actually saw one breathing today near me. An Estate no less )

 

[jberks]

The relay is called the "regulator" and yes they are around £140 available from the dealer only. I doubt tapping it will help as it's solid state. Failure is quite common. You can test them by checking the output voltages at different settings.
If you find the fan running faster than the setting, then the relay is the only thing that could cause that. They are also known to whistle, giving the impression that the fan is whining, but it's almost always the regulator.
On the 210 it's located behind the fan housing panel above the passenger footwell so is easily accessible (changed mine in 20 mins). It has a 3 pin rectangular plug feeding it through the bottom of the housing so easy to spot. I imagine the location will be similar on the clk.

 

[television]

The relay is called the "regulator" and yes they are around £140 . I doubt tapping it will help as it's solid state. Failure is quite common.

With solid state devices, the chances of a component being intermitant is almost nil, I do not find 1 component in 1000 with this problem, the problem is always started by dry soldered joints,if left,they can cause high power devices to fail, but then the fault is permenant, though one can switch using high current devices, a relay is used as you can switch up to 12 individual circuits at the same time using only one driver,low power device. Relays, once they have burnt contact, cleaning is a poor second to replacement. Burning of the contacts only happens on inductive loads, ie motors. Of the 11 control units that members have sent me, all have been solved by blanket soldering of the complete PCB.
I do not know anyone in this trade who does not give the units a hefty bang all over, both when cold and warm. Its the only way that you can be sure that the unit is OK,and wont bounce back, as that is the last thing anyone wants. Motors and sticking/worn brushes are something else.

Malcolm

 

[jberks]

With solid state devices, the chances of a component being intermitant is almost nil, I do not find 1 component in 1000 with this problem, the problem is always started by dry soldered joints,if left,they can cause high power devices to fail, but then the fault is permenant, though one can switch using high current devices, a relay is used as you can switch up to 12 individual circuits at the same time using only one driver,low power device. Relays, once they have burnt contact, cleaning is a poor second to replacement. Burning of the contacts only happens on inductive loads, ie motors. Of the 11 control units that members have sent me, all have been solved by blanket soldering of the complete PCB.
I do not know anyone in this trade who does not give the units a hefty bang all over, both when cold and warm. Its the only way that you can be sure that the unit is OK,and wont bounce back, as that is the last thing anyone wants. Motors and sticking/worn brushes are something else.

Malcolm

Fair point Malcolm and you certainly know a lot more about these things than I do.
My theory that it is solid state was based more on how it works and misbehaves. It controls the fan in a stepped or variable way based on a nominal input voltage (0-7v when I tested mine). I assumed that in order to do this via relays it would need a set of relays, each increasing the output voltage accordingly. However, if this was the case and various relays were involved, then I would expect the failure to be that one of the switch positions simply failed to have an effect. The relay before and behind in the series would continue to operate normally so if the relay for setting 3 failed you would get 1=1 2=2 3=2 4=3 5=4 etc. Also I'm struggling to see how a sticky/failed relay would cause the effects I have seen such as the switch being fixed in position 2 and the fan speed varying eratically from off up to full blast and back down again on it's own. The casing seemed to be sealed at the back with a molten plastic so without any screws I decided to leave alone and just sling it, plus if I had opened it and fixed it easily, I'd have been a bit sick that I'd just spent £140 on a new one! Any ideas how it works?

 

[television]

Hello JB, I have a lot of info I think,its going to take a couple of hours to transfer it onto my MB computer as I have a fault on this one and there 2500 pages that should open on there own, I can open the pages manualy but that will take to long.
I will come back later in the day.

Malcolm

 

[television]

The dash control unit is a logic 0-5v out, the buttons give the most problems dirty contacts,rotory controls also get dirty concts,but not as bad,the 0-5volt output goes to the fan modual (normally attached to fan box) 5 volt is the default setting,slowest speed. The fan modual converts this volage from 0 to 12volt to drive the fan. this works on the same principle as a standard 0 to 12v varialble regulator.

As you say Jberks if you have the output 0-5volt from the control unit, the fault leis elsewhere. If this is a logic circuit the ground may not be common to the car hence a meter reading of 7v.

Malcolm

 

[FOGWAR]

Thanks for the replies fellas I really appreciate the help (even if a lot of the voltage talk went over my head). Are they any places you can recommend to purchase a new blower motor if the worst comes to the worst, and what price I'd be looking at?


Thanks once again.

 

[GSM1]

Would it show on the star computer what the fault was.
A merc mechanic told be there is a way to re set the whole heating / ac system by pressing the control buttons in a certain order, he sadly had forgoten the process but assured me that it could be done, anybody any ideas.
Gary

 

[jberks]

Not sure what would need resetting really. A fan wouldn't show up on the star system and neither would the regulator. The digi systems can crash and there are diagnostic menus on them to show temps at various points but this is only on the ones with digital temp readouts. Semi auto systems like the standard E and C class units don't have this.
I would imagine 5 mins with the battery disconnected would force a reset though.