My 92 LS 400 just recently started doing some odd things. When the climate control is on Auto and the blower is on low, sometimes it'll just kick on to medium speed and stay on it. I can go to manual and set it to high or medium, but low doesn't work. If I turn the climate control off, then switch it right back on, it might go to low for a bit, then kick back to medium.

Has anyone seen this happen before? Is it the climate control sensor, or perhaps something wrong with the low speed climate control switch?

 

That sounds like a typical problem with your blower motor resistor. Located just after your blower motor (which is in the passenger side foot well). One electrical connector and a couple screws and that's it.

 

Thanks. That's good to know. Just couldn't think of the right words to search for on this forum, but now that I know what to look for it looks like there are quite a few others here who have had the same issue. I appreciate the help!