A/C problem: possible short in Heater Control Panel, Function Control Switches?

[onebad4D]

Has anyone had to mash on the left side of the Heater Control Panel (any of the left most buttons or the screw in the bottom flange will do) in order to get the A/C system to engage? I don't like having to hold the dashboard while driving down the road in order to keep the A/C running.

[Dr_Snooz]

WTF?! I've never heard of this. Has anyone been banging on the dash hard enough to break a circuit board? That's about the only thing I can see that would cause that.

[Buzo]

Sounds weird haha. The A/C needs the fan's sliding SW and the A/C button ON to engage, so maybe you have a false contact in the fan's sliding SW.
My sliding sw needs to be in an exact position to work, if I put it in the middle of two speeds it won't work.
You may need to move this fan speed selector a little bit.

[onebad4D]

When the problem began last summer I could give the dash a sharp whack and the A/C would come on. As the summer wore on the problem got worse. The hotter the ambient temperature, the more often I would have to hold/whack the dash. Once the inside temperature got cool then everything was fine. By late last summer it was malfunctioning most of the time. Last winter I experimented to see if it would work normally in the cold temperatures. It did not. Now it's pretty must constant. I have to mash continuously on the left side (for instance, the VENT button) of the control panel in order to keep it on.

All I know to do is remove the control switches from the heater control panel. It looks from the Factory Service Manual (pg 22-21) that the instrument cluster (speedometer/ tach assy) has to be removed 1st. I guess that's what they're referring to as the "gauge visor" in step 2.

Has anyone ever removed the control switch assembly? How much of a PITA is it?

[HLW]

All I know to do is remove the control switches from the heater control panel. It looks from the Factory Service Manual (pg 22-21) that the instrument cluster (speedometer/ tach assy) has to be removed 1st. I guess that's what they're referring to as the "gauge visor" in step 2.

Has anyone ever removed the control switch assembly? How much of a PITA is it?

You don't need to remove the instrument panel, just the visor that covers it. The visor includes the plastic lens and holds the retractor switch, rear defogger switch and the dashlight brightness controller. The visor overlaps the edge of the center outlet which is the only reason it needs to be removed to remove the hvac controls.

[Dr_Snooz]

I would say you have a cold solder joint in the heater button circuit board. Probably easiest to simply replace the board with a junkyard spare.