Have a87 240 s/w. the heat stays on hi all the time. the blower motor works normally, but it has HEAT!. Is there a dashpot or something that is a common problem?

thanks
dave

 

There's a heater control valve that's a common problem. AutoZone has the original metal style as part#5864. Volvo has switched over to the plastic style. Before buying the part check the cable from the slider control to the valve to see if it's still attached. Need to remove the kick panel next to the driver's right leg (left-hand drive).

 

The control valve is down by the gas pedal? I'll check the cable, I'm surprised, I expected it to be vacuum operated with all the hoses running to the control switch. How do I test the control valve, pull a vacuum and see it move?

thanks
dave

 

Assuming you have a manual climate control system, there is a cable that goes from the temperature control lever to the heater control valve. No vacuum. Test the operation of the control lever by slide it back and forth and see if it operates the valve.

The shutter actuators are vacuum controlled. Vacuum line from the intake manifold to the vacuum tank behind the dash, center bottom. The three push-button switches direct vacuum to the actuators.

The heater control valve is located right above and to the right of the gas pedal.