How does the heater work on a Volvo 850?
The ventilation damper is operated by damper motor through 2 gear segments; one fitted to damper motor shaft and the other on ventilation damper shaft. Heater (blower motor) fan speed is variably controlled by ECC output (power) stage in response to signals from ECC control module.
What happens when the AC is turned off on a Volvo 850?
If A/C is switched off using the AC OFF switch, ECC control module will cut supply voltage to relay, turning off compressor. However, this does not apply when air distribution control is in defrost setting, since A/C is always on in this case.
When to turn on the ECC in a Volvo 850?
The ECC control module normally supplies voltage to A/C relay, except when heater (blower motor) fan is off and vehicle speed is less than 20 MPH, when heater fan is off and recirculation is on, or momentarily when under full acceleration.
What’s the low pressure switch on a Volvo 850?
The high- pressure and safety switch cut power to the A/C compressor if pressure in the A/C high-pressure circuit becomes excessive, supplying a signal to ECM to start cooling fan. The low-pressure switch (pressostat) turns A/C compressor on and off to maintain pressure within limits. floor/defroster damper motor.
How to remove the a / C heater from a Volvo?
1) Remove lower dash panels. Disconnect all cable sleeves (pop out) from cables at climate control unit. See Fig. 3. Remove 4 cables from damper levers. 2) Remove control knobs and blower fan switch button from A/C-heater control panel. Remove 2 screws and A/C-heater control panel front. Remove A/C-heater control panel. Disconnect light connector.
What kind of climate control does a Volvo 850 have?
The temperature control damper motors, recirculation damper motor, floor/defroster damper motor, and ventilation damper motor are all identical, but their control range varies according to the damper being controlled.
How does the a / C compressor work on a Volvo?
Courtesy of Volvo Cars of North America. The A/C compressor electromagnetic clutch is powered by the A/C relay. Compressor operation requires that the A/C relay be activated by both Electronic Climate Control (ECC) module and Engine Control Module (ECM).
How does the a / C compressor work on a Volvo 850?
Compressor operation requires that the A/C relay be activated by both Electronic Climate Control (ECC) module and Engine Control Module (ECM). The ECM turns A/C compressor off when engine is at full acceleration, at high engine temperature, and for 5-10 seconds after starting engine.