Blower Only Works with Engine Off
04-06-2009, 09:23 PM
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1986 300E (W124)
Blower Only Works with Engine Off
1986 W124 300E
I have a confusing problem and need some help. My climate control system only works when the engine is off. As soon as the engine is turned on, the blower no longer engages. The A/C compressor will still function, vent pods will click, etc., but the blower will not engage.
In the process of trying to diagnose this, I have replaced the pushbutton control unit. I've checked the voltage coming off at the connector on the firewall, and they match what the service manual and some other good people on this board say it should. I know the blower motor works well, I've bench tested it. All the fuses are good.
The only other piece of information which may be playing a part in this is that the car's ignition key/switch was taken out and reinstalled.
If anyone can suggest my next step in diagnosing this, I would greatly appreciate it.
Thanks in advance,
Justin
I have a confusing problem and need some help. My climate control system only works when the engine is off. As soon as the engine is turned on, the blower no longer engages. The A/C compressor will still function, vent pods will click, etc., but the blower will not engage.
In the process of trying to diagnose this, I have replaced the pushbutton control unit. I've checked the voltage coming off at the connector on the firewall, and they match what the service manual and some other good people on this board say it should. I know the blower motor works well, I've bench tested it. All the fuses are good.
The only other piece of information which may be playing a part in this is that the car's ignition key/switch was taken out and reinstalled.
If anyone can suggest my next step in diagnosing this, I would greatly appreciate it.
Thanks in advance,
Justin
