1999 Chevrolet Suburban AC/heater

FACOX21

MEMBER
1999 CHEVROLET SUBURBAN
177,000 MILES

I RECENTLY HAD MY TEMP CONTROL GO BAD, AND REPLACED IT. NOW I HAVE NO AIR COMING THROUGH MY VENTS, ONLY AT THE BLOWER. IT IS ALL ELECTRICAL, NO VACCUM. THE AC AND RECIRC LIGHTS DO NOT COME ON WHEN PUSHING THE BUTTONS ON THE CONTROLLER, AND THE AC COMPRESSOR DOES NOT ENGAGE. I HAVE CHECKED THE WIRES AND FUSES IN THE DASH AND UNDER THE HOOD AND EVERYTHING IS WORKING PROPERLY. WHAT ELSE COULD IT POSSIBLY BE?

5 Replies

HMAC300

MECHANIC
48,601 POSTS

Cold be the controller is bad have it scanned

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Tuesday, August 27th, 2013 AT 12:12 PM

FACOX21

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3 POSTS

You cant scan the ac on a 99 suburban. That was pretty well useless. Thanks for all your help

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Tuesday, August 27th, 2013 AT 1:15 PM

HMAC300

MECHANIC
48,601 POSTS

Then see if the controller is getting an d putting power out. If there is no air coming through the vents meaning the dash but come through the defrosters or someplace else then an actuator is bad, try pulling the fuse for 60 seconds with key on then reinstalling as this sometimes will reset the actuators. Check the things i'm sending in the pic for power if they have power the controller should be good. You can jump the pressure switch at accumulator to see if compressor will start. It may be low on Freon as well so you should have that checked. The way you have explained this that the controller had no power. And no you can't scan a hvac controller with a autoparts scanner only a pro one will do that.

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Tuesday, August 27th, 2013 AT 3:11 PM

FACOX21

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3 POSTS

I took the blend door off at the gas pedal and found that to be the issue for the air to the vents, but the ac light and recirc light on the temp control still does not come one and the ac compressor does not engage. I checked power at the connections to the temp control and all the connectors are receiving power. I then replaced the ac relay under the hood and that didn't change anything. I noticed the fuse was real loose and could be removed without effort. Using a trick I had learned before, I placed a paper clip in the connection slots to where the relay for the ac compressor should go and wha la the ac compressor engaged and ac works. This has lead me to believe that the problem is in the fuse box itself since im getting power everywhere else. My question is, is there a way to remove and fix the issue in the wiring of the fuse box

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Tuesday, August 27th, 2013 AT 4:53 PM

HMAC300

MECHANIC
48,601 POSTS

You can replace the box or try to bend the fuse clips to make better contact with the fuse this may have to be done after removal however. Otherwise the box will need replacing.