Did you ever figure this out? My SVT is now doing the same thing, I can't see any unconnected wires or tubes though it happened when I was adding the pre 98 clock and had the radio pulled out.
So I maybe a wire or something came loose. Trouble is I can't find it if that is it.
There are two metal bulbs with tubes running from the switchs behind the center dash, and they look fine.
I checked the fuse, as I blew the dash lights fuse, but the heater fuse is fine. There is a heater relay in the interior fuse box, could that be bad?
