On my 90, my cruise control doesn't work. There is a vacuum actuator
unit on top of the engine, connected to the throttle assembly. The
hose from this unit (which operates like a bellows in reverse)
connects to a Y connector along the right-side engine bay wall. One
leg of the Y appears to run to the front of the car, the other leg
runs a short distance through a hose to a molded black plastic thing
that is mounted in the right rear corner of the engine bay, looking
towards the front.

The hose I mention is connected to one of two similar fittings on the
molded black plastic thing. The other fitting has no hose, is simply
open.

Should it have a hose?

Thanks,

Jim