Patient is 1990 Cherokee Laredo

Symptom is no cruise, no radio, and the dash clock is dimly lit.
Clock keeps time ok but never goes to full illumination.

Believing a ground prob checked under hood - battery ground and others on the right, also the woven strap and the left.
Just visual check and cleaning. No damage seen and was not that dirty.

Question is I seem to remember reading about this type of prob here or elsewhere and not able to find that info at this time.
What do these three have in common?

Also have a port on the air box that has nothing connected to it.
It is a 5/8 or 3/4 inch port on the top rear. The PCV hose is connected to another port, but I have seen pics with this upper port used for the PCV connection.
Any help greatly appreciated.
TIA
Troy