1998 S90 No heat to interior

maj357 · Post by **maj357** » 16 Nov 2014, 11:26

Everything about the Heating/Cooling systems seem to be working just fine, but when turning up the temperature selection dial in order to get heat into the passenger compartment, no heat is coming out of any of the vents or to the floor. The AC works well and the blower motor is good and strong with good air coming out of the vents, but NO HEAT!

Any help or advice would be appreciated.

Post by **jimmy57** » 16 Nov 2014, 11:48

Check to see if the heater valve on the driver's side on firewall in engine bay is stuck closed. The arm on valve should not be drawn into the vac servo on the valve. If it is unplug vac hose to see if releases. IF it doesn't then manually move it. Those have been known to stick shut due to the rubber on the throttle valve inside hanging in the bore.