Vent Selector, A/C and Recirc Not working

1995 Suburban K1500 w/5.7L w/rear air
Vent selector, A/C and Recirculate buttons. Not working..
Checked both fuse boxes. Changed A/C Relay under hood. Is there another fuse or relay under dash that could be hidden. Manual does not indicated another?
Blower works and heater. When fuse (if fuse) went, the Vent selector was on Floor.

First noticed after I hooked up neighbors trailer wires to my adaptor plug.
Link? I do not know.

Any suggestions?

I had that same problem with my "99 burben, it ended up being the heater control panel. One of the power lines on the paper part of the circuit board had gone bad. I was able to solder a small piece of wire over the burnt spot. I hope this helps.

I will take a look at that.Where is this circuit board?

I will take a look at that.Where is this circuit board?


Sorry I should have been more clear about that. You will find it behind the heater control panel. The burn portion was on the "paper?" that connects to one of the plugs. The bunt line was visible and I able to solder a line from one of the solder point to where the connector connects to the control panel.

Makes since. I searched last evening for another fuse. Nothing. Now to figure out how to get my dash apart. :) I did notice a square gray relay strapped behind the ash tray. My burban has a lot of options, alarm, gps, mobile phone. Needless to say, a lot of wires stuffed under the steering column. I am going to attempt it on my own though.
Thank you for your help.

Finally got the time to reach the Circuit Board.
The circuit board that sometimes cause trouble is the one with wires plugged into it from ac, recirc, and vent selector dials?
Mine seems to be hard plastic, instead of cardboard.
My Uncle said it is a common problem for the circuit board to go bad, like mine did. Sure is hot w/o air. :)