ac/heat control has given up the ghost.

[Kidd]

Okay I think my ac fan controler has quit. The light comes on when you turn the lights on but nothing on the display screen, where you see the fan speed and ac or heat temp settings. I've checked the fuse I think. I bought a used one from the salvage yard that they said was working when pulled. I get the same thing. Did I get a second bad one or is it something else. Thanks in advance for your help. Oh it's a 1991 silverado. With a huge 305 v8.

 

[twomanymontes]

I don't think you would have gotten a bad second unit. One that does the exact same thing is rare.

You really need to check the power and ground at the connector to the control head to be sure.

 

[Kidd]

Yeah, I did that first. I have power and a good ground.

 

[Kidd]

Is this common in these trucks?

 

[Kidd]

I don't think you would have gotten a bad second unit. One that does the exact same thing is rare.

You really need to check the power and ground at the connector to the control head to be sure.

The second one was used, not new. New is $200. I can buy new but don't want to if it's something else.

 

[burkey05]

Is this common in these trucks?

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

 

[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

Hey burkey05 thanks man that worked. I just lightly pushed in on the display and everything works now. This forum rocks. Saved be some money.

 

[Kidd]

Now if I can just stop the one I just ordered.

 

[JJHUSSY]

mine flashes weird some times, I give 'er a smack and alls good for another couple of weeks!

 

[FastOrange]

Im so glad my '94 doesnt have A/C, such a more simple design haha!