ac/heat control has given up the ghost.

[Kidd]

there was a recall on the HVAC control where the display wasnt working

http://arrc.ebscohost.com/searches?car_uuid=1143481&fa_uuid=uuid_tsb_187646992482100645233923421009365698408&filters%5Bservice_information_type_path_facet%5D=root%2Fmrt%2Fsit%2Fp5_bulletins&filters%5Bsystems_component_path_facet%5D=root%2Fmrt%2Fssc%2Fp5_heating_a_c_ventilation_defogger

also here is a link to the wiring diagram for the 91 HVAC, it may help

http://67-72chevytrucks.com/vboard/attachment.php?attachmentid=750738&d=1306114599

mine goes blank like yours, all i have to do is push lightly on the front of the control. i think there's a loose connection inside the HVAC control itself

That worked temporarily, It's blank again.

 

[Kidd]

Any one elsa have an idea?

 

[VorTecxas]

Interior swap