Thanks, Terry. I could've provided further details.

A '96 E320. The car belongs to my in-laws. I'll check the battery and re-sych it with the IR port in the mirror. See what that does.

The climate control is working fine - fan speed seems a bit slow on the high setting though. Even when both zones are in 'auto' it just doesn't seem to gust from the vents as it should. Well, as it once did.