To remove the A/C Switch in 1991 and earlier models, disconnect the negative battery cable, remove control knobs, screws retaining the top of the instrument panel center finish panel, and the finish panel itself. Then, remove knobs from the A/C Switch, take out the ashtray and ashtray bracket, and remove four screws securing the instrument panel to the A/C Switch. Disconnect wiring harness connectors from the blower switch, panel illumination light, and auxiliary fuel tank switch or rear window switch, and detach control cables. Remove the A/C Switch by undoing the spring nuts retaining each control cable pigtail to the control lever arms. For 1992 and later models, disconnect the negative battery cable, remove the trim strip above the A/C Switch and glove box door, pull the center finish panel away, and remove screws attaching the A/C Switch to the instrument panel. Then, pull out the A/C Switch to disengage electrical connectors, disconnect the vacuum harness, release the temperature control snap-in flange, and finally, rotate and remove the A/C Switch. The installation process is the reverse of removal in both cases.