ash_2009
Active Member
Dear all,
Car is w202 c36 Amg 1995.
Recently I have developed two faults which could be related or not and just pure coincidence.
1) When the car is up to normal running temp 80C, if I have the thumb dials on the heater control unit turned to blue (cold) I have hot air in both the passengers side and drivers side...side vents. There is only cold air in the centre vent. Having read around on here there is a suggestion the that duo valve in the engine bay near the fuse box is either faulty/sticking hence solenoid not closing/opening allowing only hot air in the side vents. Or it could be faulty heater control unit in the centre console.
2) At the same time and more randomly, when the car is running, the round fan control and air position control dials and the heater control unit are flashing in a continuous manner a bit like the hazards. When I turn the main head lamp beam ON the flashing stops....when I turn the beam off the flashing starts again. After searching around for this I have come across several posts saying it could be a faulty alternator voltage regulator which is attached to the back of the alternator and the brushes are shot and hence when you increase load the flashing stops.
So is this just two separate things happening or could it point the the heater control unit on its way out!!
So before I go about buying new heater control unit and/or duo valve is there some things I can do to eliminate one or the other to get to the bottom of both these issues?
Thanks
Car is w202 c36 Amg 1995.
Recently I have developed two faults which could be related or not and just pure coincidence.
1) When the car is up to normal running temp 80C, if I have the thumb dials on the heater control unit turned to blue (cold) I have hot air in both the passengers side and drivers side...side vents. There is only cold air in the centre vent. Having read around on here there is a suggestion the that duo valve in the engine bay near the fuse box is either faulty/sticking hence solenoid not closing/opening allowing only hot air in the side vents. Or it could be faulty heater control unit in the centre console.
2) At the same time and more randomly, when the car is running, the round fan control and air position control dials and the heater control unit are flashing in a continuous manner a bit like the hazards. When I turn the main head lamp beam ON the flashing stops....when I turn the beam off the flashing starts again. After searching around for this I have come across several posts saying it could be a faulty alternator voltage regulator which is attached to the back of the alternator and the brushes are shot and hence when you increase load the flashing stops.
So is this just two separate things happening or could it point the the heater control unit on its way out!!
So before I go about buying new heater control unit and/or duo valve is there some things I can do to eliminate one or the other to get to the bottom of both these issues?
Thanks