Only on a clear sunny day, “high pressure” my 1996 taurus wagon makes an occasional honking sound at about 65-70 mph. It sounds like it comes from under the dash, or maybe the firewall. I tried adjusting the ac controls on and off,I tried turning the cruise on and off. I suspect that a rubber diaphram inside some control is vibrating, but I really don’t know. I’ve had this car almost since it was new, and it has 189,000 miles. It still runs great.
I guess it didn’t bother you much for the first 14 years .
FUNNY, actually it’s only been doing it for a couple weeks. However I did find that it is a great conversation stopper. When someone hears it they say " what the heck is that" thus ending whatever they were talking about. So I do see some advantages to leaving it alone!!
A 14 year old Taurus that has gone 189,000 miles and runs great has something to toot its own horn about.
It does sound like something that is vacuum controlled.
Thanks, I guess I’ll get under that dashboard and trace it out. Now, where’s that shrink ray?