CLK230 Heater Probs

[jonb25]

Hi

I have a 1998 CLK 230 and the heater will not work.

The display all works fine, I can turn the blower up and down and adjust the temperature, but nothing comes out of the vents.

If I put the blower onto maximum and heat upto maximum and drive along at about 60 - 70mph then eventually the car will warm will up slightly, but nothing seems to be coming out of the vents on the dash.

I have been told it could be the Heater Fan Resistor (which merc have for £166 + vat)

Has anyone got any other ideas or could it be the Heater Fan Resistor (if it is, does anyone know where this is located and is it easy to change?)

Thanks in advance for any help

 

[jberks]

The fan shouldn't be that difficult to check. I have changed the resistor pack(regulator) on a W210 and its pretty easy, but as mine was whistling and the speed was up and down randomly, it was a pretty easy diagnosis.

Some of this may differ slightly on the CLK but the principle should be the same. The regulator on the W210 is under the fan assembly behind the glovebox above the passenger footwell. Looking ath the under-side of the fan assembly, you should see a rectangular plug with 3 wires. Remove the plug and then unscrew and unclip the bottom cover onf the housing. The regulator is a triangular silver box with cooling fins. The 3 wires feeding it are +ve, -ve and speed signal. The speed signal comes from the switch or controller and should vary say between 0 and 5v depending on the setting. This is the easiest to check and will confirm that the controller is ok. From there, check the voltage coming out from the spade connectors. If they remain firmly at 0v (and the +ve and -ve in feeds are ok) then that's your problem. If not, you may need to go further into the fan itself. I have heard of the brushes failing, but these can be replaced too.

 

[jonb25]

ok cool

will check that later and let you know

thanks for your help!

jon

 

[joe bloggs]

Blocked dust filter, below pass. dash panel

 

[jonb25]

Will look for that as well. Can you describe anymore about the blocked filter and how to replace it?

Thanks in advance

Jon