Climate Control gone hot...

[Dan Sinclair]

Hi all,

Well, I violated Audi Rule #1 - if it's not broken, don't touch it, breath wrong, or look in it's general direction...

1990 Coupe Quattro, US Spec.

The problem:  My Climate Control suddenly seems to be pushing out abnormally warm air when in the ECON mode.

I usually run in ECON most of the time, and have it set at 65-70 degrees.  This generally just blows cool vent air into the cabin for ventilation.

Long-winded background:

I was fooling with some stereo stuff over the weekend and did three things - one of which I suspect is related to the new problem:

1.  I ran some wiring under the dash, into the center console and to the stereo head-unit - located immediately above the Climate Control unit. (I checked twice to see if I knocked off a hose or wire - didn't look like it).

2.  While looking for a hole in the firewall to run a wire to the battery, I found that the intake area for the Climate Control blower/fan unit was partially covered with dead leaves and debris - so I cleaned it out, vacuumed out the debris, and the air duct is nice a clean now.

3.  I found a vacuum line just in front of the battery that was disconnected.  I suspect I may have knocked it off myself taking the battery cover off, but I can't be sure.  Don't know if it was off prior or not.  It's connected now though.  It's a yellow vacuum line that runs to a small 'pot' down by the block, with a fuel line running into it.

Theories?  I did notice a two wire sensor near the blower/fan intake that I cleaned up - is it possible that the leaves were blocking this sensor, and my climate control is now working properly, where prior it was obstructed?  I have my doubts.  The other oddity was on a 60+ degree day, my 'outside temp' was reading 31 degrees (way off...).  It's always been pretty accurate prior to this weekend.  Is it possible one of the sensors just coincidentally died and is throwing off the temperature feedback - forcing the heat on when it shouldn't?

I don't understand this system very well, so I'm not sure where to look.

Thanks,

Dan
1990 CQ