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A/C Controller issue 1992 C1500

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Old May 6, 2018 | 5:12 PM
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Default A/C Controller issue 1992 C1500

HI EVERYONE! I have a problem with the digital A/C control in my 1992 C1500 Silverado. The Controller just quit opening the cabin air flaps. There are flashing horizontal “arrows” on the left side that weren’t there before. My garage guy reached under the hool and tugged at a plug on a sensor near the thermostat, snd suddenly the Controller was OK again. Today (3 days later), it’s back to flashing. I have a spare, good Controller, and it behaves the same when swappef. Not sure what that sensor is, but I’m sure it’s the problem. Could someone help me with this? I suspect a bad connection or a floating ground somewhere. THANKS FOLKS!!
Sandy
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Old May 13, 2018 | 11:42 AM
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also check the fuse relay box inside the hood near the driver side, that square cube relay can go bad as well (i recently had to replace mine as well).
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Old May 14, 2018 | 4:32 PM
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THANKS, BRIAN! That may be the weak link. I'll have a closer look!
Sandy
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Old May 14, 2018 | 4:49 PM
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Originally Posted by sandygerli
HI EVERYONE! I have a problem with the digital A/C control in my 1992 C1500 Silverado. The Controller just quit opening the cabin air flaps. There are flashing horizontal “arrows” on the left side that weren’t there before. My garage guy reached under the hool and tugged at a plug on a sensor near the thermostat, snd suddenly the Controller was OK again. Today (3 days later), it’s back to flashing. I have a spare, good Controller, and it behaves the same when swappef. Not sure what that sensor is, but I’m sure it’s the problem. Could someone help me with this? I suspect a bad connection or a floating ground somewhere. THANKS FOLKS!!
Sandy
Originally Posted by Brian D Jones
also check the fuse relay box inside the hood near the driver side, that square cube relay can go bad as well (i recently had to replace mine as well).
BRIAN...there seems to be only one mofule on my truck, in that location has a blue multi-pin plug and is secured to the Firewall with three Philips screws. Is THIS the relay module you are referring to?
Sandy
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Old May 18, 2018 | 12:07 PM
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Originally Posted by Brian D Jones
also check the fuse relay box inside the hood near the driver side, that square cube relay can go bad as well (i recently had to replace mine as well).
HELLO BRIAN!! Where exactly is this “fuse relay box”? On my ‘92, the only things nesr the driver’s side are the the Winddhield Wiper Motor and the Cruise Control Module. It would really help if I knew what I was looking for. “Indide the hood”, does that include the Firewall and the Fender Well too? Thanks for clearing this up!
Sandy Gerli
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Old May 20, 2018 | 1:30 PM
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https://www.justanswer.com/chevy/3k5...ompressor.html

this is a pretty decent picture of your relay location, the ac connector is number 1, number 3 is your relay. After looking up your specs and everything, it seems your style is different than mine, my 98, has the relay inside the driver side area under the hood.
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Old May 21, 2018 | 11:47 AM
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Default Under-dash A/C Conttoller Diagram

Thanks for the diagram, Brian. I suspect that the Mode Motor(?) may have a poor connection or a floating ground? Would the Mode Motor be responsible for opening the air outlet vents gradually between the Defroster and Floor? They worked perfectly up until about a week ago.
Ssndy Gerli
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