Inline in one heater hose underhood near the HVAC box (right hand side underhood.)
You take it to a AutoTech.
The vacuum control valve for the heater on a 1992 GMC Suburban is typically located on the heater control assembly, often behind the dashboard. To access it, you'll need to remove the lower dash panel and possibly the center console, depending on the specific configuration. Once you have access to the heater control area, you can locate the vacuum lines connected to the valve. Be cautious with the electrical connections and vacuum lines during removal and installation.
In my 98 E350 6.8 it is under the dash. you have to pull the dash off to change it
The heater control valve on a 1992 Pontiac Grand Prix is typically located in the engine compartment, near the firewall on the passenger side. It is connected to the heater hoses that run between the engine and the heater core. To access it, you may need to remove some components or hoses for better visibility. Always refer to a repair manual for specific guidance and safety precautions.
The 1992 Acura heater control relay switch can be found beneath the passenger side dashboard. The heater control relay switch will be a few inches above the kick plate.
OK the heater is not letting the heat into the cab of my truck-I think the switch that controls the deflection doors is broken what is my answer the best thing to do.
on the right side of the throttle body
remove the glove box and there are three relays one is for the control door
It can be several things including the cont valve,if it has one, stopped up heater core, or thermostat. Have it checked out and don't throw parts at it as this can be expensive.
it is located on the passenger side valve cover
typically in the valve cover.
its on the back of the valve cover.