The control valve for the heater on a 1998 Cadillac typically is located in the engine compartment, along the heater hose routing. It is often found on the firewall or near the engine block, connected to the heater core. To access it, you may need to remove some surrounding components for better visibility. Always consult the service manual for your specific model for precise details.
No, the inside temp is controlled by a temp door inside the heater box.
behind you glove box
It is at the rear of the intake manifold, follow the heater hose. there is a flow door under the dashboard with a cable connected is that the control or does the valve body at end of intake still control it?
I just changed my heater control valve today. I was able to get the part from Amazon for $98. If you get it from Autozone or O'Reilly's you can expect to pay around $130. The part Motorcraft # YG-378
In my 98 E350 6.8 it is under the dash. you have to pull the dash off to change it
Thermostat is missing or stuck open, coolant level is low, heater core is plugged or heater control valve is stuck closed.
Have you used any stop leak in rad.? If you have pull off heater hoses and back flush heater core. Also check hot water control valve for heater.
cable
98 chevy lddle control valve
To change the heater control valve in a 1990 Oldsmobile 98, first, ensure the engine is cool and disconnect the battery. Locate the valve, typically near the firewall on the passenger side, and remove the hoses connected to it by loosening the clamps. Unscrew the mounting bolts to remove the old valve, then install the new valve in reverse order, making sure the hoses are securely attached. Finally, reconnect the battery and check for any leaks after starting the engine.
Check coolant level Check to make sure heater core is not air bound Replace thermostat Check the operation of the heater control valve/cable
no.fully unajusteble