No HVAC control and stuck on defrost also just putting out cold air . last week we talked about the vacuum control switch.
Also i have no air horns.....the last owner installed an auto horn . Am sure there's a valve that just releases the air to the horns ... Thanks for all help.
There is a solenoid that controls the horns under the lift up dash. On mine for some reason the connector would come loose on one of the wires from time to time and then the horns would not work. Check the wiring at the solenoid and tighten up the connections. The HVAC sounds like a vacuum problem not opening the doors in the plenum. Do a search for dash air , lots of info.
Gary B
Thanks Gary.
On my 91 the solonoid is on the back of the air pressure gage under the flip up dash.
I took my solenoid off with plans to replace. Decided to experiment w/ it first. Solenoid was just stuck. I forget what I sprayed into it, probably WD40, but it has been working for two years now.
Good luck.