Another HVAC issue thread
 

The HVAC unit in the car I recently bought ('92 SC400) appeared dead (no display, controls didn't work). I got another one.

Today I tried installing it and, of course, it doesn't work. After checking fuses I noticed that it may be possible an important connection isn't being made to the rotary switch labeled "TEMP AUTO". I'm not sure though because it's difficult to determine if the place that looks like it could be a connection truly is.

My question is, how many connections should be made to this unit that has the dual rotary knobs, one as labeled above and the other that controls power and volume to the sound system?

This first image is of the controls.

http://img526.imageshack.us/img526/2751/img00015.jpg

This next image shows the back of the controls. The concern is whether a connection needs to be made on the upper (black) part of this unit. Even close study of it is inconclusive.

http://img248.imageshack.us/img248/8075/img00014z.jpg

This image shows three lines directed toward this part of the unit. One of which connects to the rotary unit in question, another for the hazards and the third appears to be a dead-end.

http://img514.imageshack.us/img514/8636/img00016w.jpg

This last image is a rotten pic of the dead-end line.

http://img229.imageshack.us/img229/3972/img00017j.jpg

Is it that this is too newbish to respond to or that nobody has the answer? Seems like somebody would know... :confused:

When I was taking apart my console (mine is 99) there were only two connectors. One going to those volume/climate knobs and another to hazard switch. There was no third one. Are you sure you didn't pull that from cigarette lighter?

Btw, climate unit WILL work and turn on even if those knobs are disconnected. Make sure that all three connectors are connected tightly at the back on climate unit.