It's on an SC300 near the passenger side firewall. Looks to have coolant lines hooked up to it. I don't have an SC300 fsm, but can someone help me identify what it is and what it does exactly??




Thanks.

 

iunno what it is, but in a basic thermo system like this there's only so many parts.
i'd guess that is the throttling valve. it creates pressure to keep flow motion going

 

I think you are talkin about the heater control valve. or somethign like that name. Mine was leaking a little bit a while back. Dealer item only 250$ish dollars. i nver replaced it though. I put some sealent on it and it stoped leaking.

 

What he said its the heater valve. Did you stop getting warm air? I had that problem. What i did was take the thin cable and put it directly on the extension from the valve. Walla heater works again. Hope that helps.

Also if that doesnt work, you might want to check the solenoid. The little motor that opens and closes the valve might be shot.

 

Its just a vacuum operated plunger....no motor in it. The solenoid closes and opens the plunger to the vacuum line. Yes, hooking the vacuum line directly to the plunger will work, but it will take the car longer to heat up and will run water through the heater core at all times, which has its disadvantages as well.

 

Thanks for correcting me...i wasnt sure if there was a motor or solenoid....but yeah mine heats up now .....before in the cold mornings when i needed it......it was dead ....but now after running the line directly it works

 

why would the plunger use a vacuum source to open and close access to the heater core? would that mean everytime you let off the throttle/stomp on the throttle it would open and close repectively? can you tell by the pic if it's hooked up right?

 

Which is why if you look slightly up the vacuum line you will see a one-way valve that "traps the vacuum." Yes, it is hooked up correctly, but that sensor is prone to failure (mine failed on my 96').

 

thank you!

any idea on what those 2 black wires on top go to / do?

 

turn it on or off.. If your valve is faulty and u dont get heat.. tie a zip tie around it to keep the valve open.

 

Basically vacuum is feed into that sensor (which is turned on/off by the wires, which come from the climate control/ecu), then if the sensor is "open" it allows the vacuum source to continue on into the plunger which opens the heater core to coolant flow. When the sensor "closes" it cuts vacuum from going into the plunger, thus closing the heater core off to coolant flow. Rather complex for something that on most other cars just has a cable going from the thermostat slide to the heater core valve that opens when you turn it to hot and closes when you turn it to cold.