A/c Works Fine, But Heat Doesn't. Why?

[spencerfunk]

My 1992 SC 300 was working fine till a couple of weeks ago. The heat stopped working. The A/C works fine. The same problem where my heat stopped working, but my A/C was working happened for a day back in January, but the problem went away. Now I have the problem and it hasn't gone away for a couple of weeks. Does anyone know what my problem is?

Spenstar

[sjc6765]

usually the vacuum switching valve located on the firewall, passenger side. follow the hot water line, you will see a valve that is vacuum opperated, but controled by an electric solenoid. usually that solenoid goes bad.

[spencerfunk]

usually the vacuum switching valve located on the firewall, passenger side. follow the hot water line, you will see a valve that is vacuum opperated, but controled by an electric solenoid. usually that solenoid goes bad.

does anyone know how much that usually costs? also, is that something fairly easy to do myself?

[sjc6765]

There are a couple listed on ebay right now for 100.00. Easy 1 hour change.

[UCF3]

You might need to be patient when you replace the vacuum cable.