My heater ain't got no heat!

[SSSupras4ever]

Ok, so I bought my first Supra a couple months back. Summertime and the hottest on record in Seattle, so I never bothered to check the heat!

Now, September is here, and mornings are cold. Afternoons are still nice (so far) but it's not going to last forever. I need to get my heater fixed. Here's the symptoms...

The blower motor works perfectly. In every setting. Auto, low, medium and high. It's the temperature control that doesn't do squat. I have checked all the fuses I can find, but to no avail.

The next thought was the VSV. I get no readings on the two electrical connectors that plug into the VSV, so I wonder if that may be the problem. Anyone know what the reading should be on that?

Also, I can feel no vacuum on the hose at the top of the VSV. Possible problem #2?

The next thought is the heater core itself, but I would hate to rip apart the dash and replace an expensive item like a core if it's not even the problem. Any way to ops check that before traveling down that ugly road?

I've read past posts of similar problems and have found no solution. I could really use some advice for another road to try.

Help me out! I'm freezing my ass off!

[jefe_not]

Take a quick look at this thread - similar (but opposite) problem but it explains a few things...

http://forums.celicasupra.com/showthread.php?t=50097&highlight=heat+cold+air

[jtwhitehead]

sounds like a vacuum problem. check for it at the diaphram under the hood at the fire wall and under the dash at your blend door. thats where my problem was.

[one2spooku]

I am not sure who did the write up. There is a nice description of the heating system floating around on the site some where.

http://www3.sympatico.ca/dean.anderson4/HeatingSystem.htm

Found it :)

It may give you some insight.
The heating system is pretty fun to play with. The heater core is a pain to get to but it can be done.

I promise the info is hidden on the site. Every year we get a lot of heater threads. I did my core last year. The actual water valve up on firewall is available new still from Toyota I believe. Quite a few parts could be the problem. Lots to read.

[SSSupras4ever]

Thanks Garrette,

I've been reading and processing all that information. I'll be doing some major checks tonight, tomorrow and this weekend until I get it right. I'm really trying NOT to tear the dash apart, but if that's what it takes... then so be it.

I appreciate everyones input so far. It's helpful. Thanks guys!!!

[CarFreek]

If you are at home Saturday afternoon, maybe I can come help. Sounds like if you bypassed switching valves and applied direct vacuum to both the Heater Door port on firewall , and the Water Valve, that could help determine problem. Water Valve could be physically frozen and not allowing hot water into heater core-And vacumn inside cabin from firewall port could be bad also, but those quick and dirty tests can help...