Just a heads up for those of you with ACC systems. My '93 960 had been holding cabin temperatures lower than the level set on the dial (at least for heat, where 72 was more like 66-68 over the last year or so). For a while I thought this was going to be a problem with the dash computer or some other complex piece of the automatic system. Some had suggested that it was likely to be the sun sensor located on the top right of dash at the speaker. On studying the system more, I settled on the most likely problem as being the temp sensor located in the overhead dome light fitting, where there is a little hole and air is sucked in past an electric sensor. Note that there were no fault codes showing. Just before I ordered a new sensor, I found the answer - dirt collected in that tube in the dome light leading to the sensor. The fix turned out to be a couple of squirts of an electrical contact cleaner into the small hole where air is drawn into the temp sensor in the dome light. The excess runs out, and in my case, brought out a bunch of black dirt/ dust that was insulating the sensor. Don't even have to drop the dome light, although that is only a press fit.

Hope it helps someopne out there.

Mike Sullivan