00 GMC Sierrq heater issue - The 1947 - Present Chevrolet & GMC Truck Message Board Network

edgein72 · 11-10-2018, 03:01 PM

I have what is probably a silly question. My heater blows hot air but the selector doesn't work so it only aims at the floor. Also the AC doesn't work. Could it be as simple as replacing the dash unit (pictured here). I'm a tad short on funds so I don't want to take it to a shop. I have a 99 Tahoe in the driveway that I was going to check to see if the units are the same because the heat worked perfectly in there. What else might I look for to get the direction selector to work ?

**hatzie** · 11-10-2018, 07:31 PM

It's probably the gears in the blend door motor.

The Tahoe is likely a T400 chassis.

11-10-2018, 03:01 PM	#1
edgein72 Registered User Join Date: Jun 2012 Location: Hurley, New York Posts: 9	00 GMC Sierrq heater issue I have what is probably a silly question. My heater blows hot air but the selector doesn't work so it only aims at the floor. Also the AC doesn't work. Could it be as simple as replacing the dash unit (pictured here). I'm a tad short on funds so I don't want to take it to a shop. I have a 99 Tahoe in the driveway that I was going to check to see if the units are the same because the heat worked perfectly in there. What else might I look for to get the direction selector to work ? Attached Images

11-10-2018, 07:31 PM	#2
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,912	Re: 00 GMC Sierrq heater issue It's probably the gears in the blend door motor. The Tahoe is likely a T400 chassis. __________________ 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.

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