AC/blowers playing up

[paulfoel]

My C class has always been a bit wierd when you turn the blowers on - it seems to take a few seconds to start up when you first turn it on.

Trouble is it now seems to take even longer. You can turn the blower on and it wont actually start for a few mins after you've driven down the road.

Thought it might be a lose wire or something but it seems that once its started its OK. Weird or what?

 

[jberks]

The 2-5ish seconds wait is normal enough. Any longer isn't. Merc do not seem to be able to get a reliable fan regulator. Symptoms range from not starting through random speed (mine) and even being on, flat out, when the ignition is off. Almost always the regulator and £100-150 ish to fix.

 

[paulfoel]

The 2-5ish seconds wait is normal enough. Any longer isn't. Merc do not seem to be able to get a reliable fan regulator. Symptoms range from not starting through random speed (mine) and even being on, flat out, when the ignition is off. Almost always the regulator and £100-150 ish to fix.

Hmmm. Sounds like thats the deal with mine then. What exactly does the fan regulator do anyway?

 

[jberks]

Look up fan regulator on the forum and you'll find lots of detailed descriptions, but basically - takes a small voltage in from the switch (0-7 volts ish) and sends out the appropriate heavier current to the fan.

 

[geoffrey9492]

How can I check fan regulator.
I have 12 volts between brown and blue.
No volts to fan.
Fan works OK when connected direct to battery