W203 C240 2005 Auxiliary Pump Dilemma
02-24-2021, 12:08 AM
#1
Newbie
Thread Starter
Join Date: Mar 2018
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
2005 W203 C240 sedan
W203 C240 2005 Auxiliary Pump Dilemma
Hi
While trying to resolve a no heat in my 2005 C240 unless control is switched to High I examined the auxiliary coolant pump for operation and found it wasn,t turning, even when rest was turned on. I first checked the connector and found it had a continual 11.6 V even with every thing turned off. I then checked the pump motor by applying 12v from battery. It works fine. So if the connector has around 12V continual and the pump operates when 12V is applied why does the connector go to 0 V when connected to pump . Why is the voltage disappearing?? and where should I look to resolve issue.
Cheers
Ric
While trying to resolve a no heat in my 2005 C240 unless control is switched to High I examined the auxiliary coolant pump for operation and found it wasn,t turning, even when rest was turned on. I first checked the connector and found it had a continual 11.6 V even with every thing turned off. I then checked the pump motor by applying 12v from battery. It works fine. So if the connector has around 12V continual and the pump operates when 12V is applied why does the connector go to 0 V when connected to pump . Why is the voltage disappearing?? and where should I look to resolve issue.
Cheers
Ric
