A/c /heater controls are not working 1999 honda accord

SOURCE: 1999 Honda Accord Coupe

See an example
DISASSEMBLY 1. Remove the suction pipe and the O-ring from the oil pump.
2. Remove the rear cover with the gasket and pins. 3. Remove the cam ring. 4. Remove the rotor and vanes. 5. Remove the front side plate.
6. Remove the inner and outer O-ring. 7. Remove the spring. When assembling, use a new gasket and O-ring.
8. Remove the pulley nut with the spring washer. 9. Pull off the pulley and the woodruff key. 10. Remove the snap ring using snap ring pliers. 11. Drive out the pulley shaft with the bearing. If necessary, use plastic hammer

SOURCE: 1999 honda accord ac / heater fan control

Hi! The speed control is defective.The terminal 1&2 could either b worn or burnt out.

SOURCE: 1999 Honda accord dashboard clock light

use a eyeglass flat screww driver to pry the clock assembly up and out , disconnect the clock assembly and remove the bulb by twisting the the blue or sometimes grey round plastic bulb bottom to remove it from the assembly. install new bulb , twist clockwise to lock in place , reinstall assembly

SOURCE: 1999 Honda Accord heater not blowing hot air

Sounds like a thermostat or cooling system issue. Change the fluid and the thermostat. It will do your engine good so it's money well spent.

SOURCE: This a 1999 Honda Accord.

The difference is semantics. The A/C/Heater control switch is located in the A/C Heater control panel. So I guess it could be said either way - same thing. The ONLY part of the A/C/Heater Control Panel that is serviceable alone is the blower motor switch assembly. It can be removed from the back of the control panel and replaced. The rest of the control panel (including the A/C request switch) is serviced only by replacing the entire control panel.

Does the A/C request switch actually not push in? Or does it just not light up when you push it? Is the A/C working? Are either of the two fuses to the control panel blown? If so, we need to find out WHY! Does the control panel ground circuit have good continuity to the battery negative post? Is the ECM showing that it is receiving the command from the switch? I am not expecting you to have answers for all of these questions, I am simply pointing out some of the things that should be checked before replacing the control panel....So your research can be more complete. :)

Also, you may want to review these articles for a little "research project" They do not address your problem directly, but they are relevent in a general kind of way.
Where's The Fuse?

What Else Could Be Wrong?

ANYWAY, it sounds to me like some diagnosis needs to be performed before running out and spending any money on parts. Give me some more information about the exact nature of the problem and maybe I can help you figure out what to do.