Heater/ac Door Stuck?

[johnpend]

Greetings!

After a minor accident, my AC and heater stopped working. My mechanic replaced a couple of AC parts and huzzah! I had plenty of cold arctic air! Then the seasons changed and I tried to turn on the heater. The fan works fine, but only cold air came out. I took the car (94 ls400) back to the shop and Randy tried checking out some cables, etc. He said everything seemed to be working ok, except no heat, but he couldn't be sure of the cause because he needed to investigate further but had to leave work at noon that day. He suspected the heater core might be bad and asked me to bring the car back the next day for more tests.

As I drove home, dreading the cost of replacing the heater core, I felt something coming out of the dash... HEAT! And lots of it! Problem solved, I thought. Wrong.

The AC no longer blows cold air, only hot. And I can't get warm air. Only really, really hot air.

I suspect the Randy the Mechanic flipped the door from ac to heat while he was investigating. Is there some sort of control that would mix cold and hot air to produce warm air?

Any and all replies will be greatly appreciated. Thank in advance! :D

[steve2006]

Hi,

There are a lot of control flaps and servos in the heating cooling system and as Toyodiy have now had to remove thier exploded diagrams I cannot give you the link to them which would have helped no end.

One thing to check is the heater control valve on the engine bulkhead just make sure it is opening and closing when required.

[johnpend]

Hi,

There are a lot of control flaps and servos in the heating cooling system and as Toyodiy have now had to remove thier exploded diagrams I cannot give you the link to them which would have helped no end.

One thing to check is the heater control valve on the engine bulkhead just make sure it is opening and closing when required.

Thanks much, Steve.

It's a shame that they had to take down those schematics. Sigh.

[curiousB]

quote]

It's a shame that they had to take down those schematics. Sigh.

You can get the diagrams if you sign up as a member of the site. Just follow the registration procedure and within a couple days you'll be back in business.

[RDM]

The main valve is located on the firewall, right behind the engine. Adjust the temp control and watch the cable, make sure it moves fully in both directions. That will get you started.