Is there a permanent fix for the split AC system in GMT800s? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

WyattTX · 01-19-2019, 02:26 PM

In my 2004 2500 HD 4x4, the one side of the cab blows cold air, and the other doesn't. It has done this 2 times before, and it was fixed with a new actuator motor both times. I'm getting tired of this. Can I just eliminate the blend door entirely, and just not have a split system (assuming that's all that's blocking the air flow.)? All I want is the same air temperature, and pressure coming out of all the vents. I couldn't care less about having a split system. I just want cold AC. I'll be honest I dont know how these HVAC boxes are set up, so I would appreciate some input before I make the situation worse. Thanks.

**hatzie** · 01-19-2019, 05:41 PM

Usually it's stripped gears in the actuators. My Gen 8 Impala has the same issue.

If you're killing actuators fairly often you might want to look into how hard it is to move that blend door. The linkage may be worn or have dirt or mice or some other obstruction keeping the door from moving freely.

WyattTX · 01-20-2019, 03:10 PM

Thanks I'll be sure to inspect that.

homemade87 · 01-21-2019, 09:23 AM

When you installed a new actuator did you do a recalibrate process . If no it could be why they are not lasting . It may be trying to go past its perimeters and damaging the unit . It has to learn the limits . It is odd that 2 has failed . As said above , be sure there is no obstruction .

Just google up a recalibration process and try that first . If no help it mat require another .

I don't know how to eliminate any of the functions but this may help solve the problem .

01-19-2019, 02:26 PM	#1
WyattTX Registered User Join Date: Nov 2015 Location: Down south Posts: 518	Is there a permanent fix for the split AC system in GMT800s? In my 2004 2500 HD 4x4, the one side of the cab blows cold air, and the other doesn't. It has done this 2 times before, and it was fixed with a new actuator motor both times. I'm getting tired of this. Can I just eliminate the blend door entirely, and just not have a split system (assuming that's all that's blocking the air flow.)? All I want is the same air temperature, and pressure coming out of all the vents. I couldn't care less about having a split system. I just want cold AC. I'll be honest I dont know how these HVAC boxes are set up, so I would appreciate some input before I make the situation worse. Thanks.

01-19-2019, 05:41 PM	#2
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,912	Re: Is there a permanent fix for the split AC system in GMT800s? Usually it's stripped gears in the actuators. My Gen 8 Impala has the same issue. If you're killing actuators fairly often you might want to look into how hard it is to move that blend door. The linkage may be worn or have dirt or mice or some other obstruction keeping the door from moving freely. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

01-20-2019, 03:10 PM	#3
WyattTX Registered User Join Date: Nov 2015 Location: Down south Posts: 518	Re: Is there a permanent fix for the split AC system in GMT800s? Thanks I'll be sure to inspect that.

01-21-2019, 09:23 AM	#4
homemade87 Registered User Join Date: Apr 2010 Location: Guntersville Alabama Posts: 1,073	Re: Is there a permanent fix for the split AC system in GMT800s? When you installed a new actuator did you do a recalibrate process . If no it could be why they are not lasting . It may be trying to go past its perimeters and damaging the unit . It has to learn the limits . It is odd that 2 has failed . As said above , be sure there is no obstruction . Just google up a recalibration process and try that first . If no help it mat require another . I don't know how to eliminate any of the functions but this may help solve the problem .

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