Everytime I depress the horn, I hear a clicking sound. Sometimes for w split second, I can hear it making a weak effort. Do I need to just replace the horn, or is it something else?

One either the ground is shorting out, rusted or both and you are only getting a slight contact giving you the occational low sounding horn. Or two, your horn is shot.

Oddly enough, it works again. I think it might be temperature related. It gets too cold, it stops working!

Oddly enough, it works again. I think it might be temperature related. It gets too cold, it stops working!

might be cause by damp/condensation. try spraying WD40 or another waterdispersant on the horn contact this may help.

My Cav has done that since it was first purchased it's a 90. For me I assume its a loose connection. I would just wiggle it and it would go back to working for awhile until it became loose again.
dleh