Can't Change Air From Vents To Heater - The 1947 - Present Chevrolet & GMC Truck Message Board Network

DANL · 11-23-2002, 11:36 PM

Anyone have advice for problem with the HVAC system on my 72 K5. I can not divert the air from the vents to heater or defroster. When I move the control lever, the cable moves arm on box. I can also hear the flap moving inside the box. But the air continues to come out of vents. Any recommendations or advise would be appreciated.
Thanks in advance.

...Dan

Ackattack · 11-24-2002, 12:39 AM

I've had the same problem. The diverter flap was broken along the bar where it rotates. I ended up super gluing it back together and it works. You could also by a new diverter box or a salvage yard piece, but I'm cheap.

DANL · 11-24-2002, 02:37 PM

Thanks Ack.

...Dan

Hooter · 11-24-2002, 08:11 PM

Isnt there a rubber gasket around the door? If there is it might be all cracked
I had a similar problem on my 77 silverado, turns out the heater box was full of pencils, pens, nails and a screwdriver. Don't store crap on the top of the dash

DANL · 11-24-2002, 11:41 PM

Thanks Hooter!
I plan to get into this weekend.

...Dan

mtdave2 · 11-25-2002, 01:25 AM

ya im sure its that door. it breaks right near the pivot pin. im even cheaper than you guys, i got 2 large washers and some really good epoxy. glued 1/2 the washer on the door and the other 1/2 on the part still connected to the pin.. works well. almost 2 years no trouble

DANL · 11-25-2002, 09:48 AM

Thanks MT.
Looking forward to it not costing much.

...Dan

johnnyp · 11-25-2002, 10:22 AM

Want a really cheap fix? Here's how the PO solved the problem. Works ok but it can be a little tricky to close or open while you're driving. I decided to go with a new box.

chevy2racr · 11-25-2002, 04:18 PM

I was thinkin about doin somethign lke the last pic, but I'm not sure what you guys are sayin is broken. mine I took apart to replace the heatr core last winter and it didn't work whn I got it togeter, took it apart and pushed the flap up so it was in the heater vent direction. summer, I slide the lever and it goes back, took itapart this fall to flip it again, and just recently the defrost to heater changer stopped workin. I can move the slide but it stays at little on defrost, rest of heater(floor)
any ideas?

chevy2racr · 11-25-2002, 11:49 PM

ttt

DANL · 11-26-2002, 01:31 AM

That is deffinitely cheap Johnnyp.
Chevy2racr I think my problem is with the first diverter controlled by the ac.

...Dan

chevy2racr · 11-29-2002, 04:09 PM

any ideas for me to look for?

DANL · 11-29-2002, 07:35 PM

I am not an expert, and not sure I understand your problem, but it could be cable related. Is your cable moving diverter arm required distance?

...Dan

11-23-2002, 11:36 PM	#1
DANL Senior Member Join Date: Mar 2002 Location: Bartlett, TN Posts: 348	Can't Change Air From Vents To Heater Anyone have advice for problem with the HVAC system on my 72 K5. I can not divert the air from the vents to heater or defroster. When I move the control lever, the cable moves arm on box. I can also hear the flap moving inside the box. But the air continues to come out of vents. Any recommendations or advise would be appreciated. Thanks in advance. ...Dan

11-24-2002, 12:39 AM	#2
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,524	I've had the same problem. The diverter flap was broken along the bar where it rotates. I ended up super gluing it back together and it works. You could also by a new diverter box or a salvage yard piece, but I'm cheap. __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index

11-24-2002, 08:11 PM	#4
Hooter My other Love Join Date: Aug 2001 Location: Castlegar B.C. Canada Posts: 4,085	Isnt there a rubber gasket around the door? If there is it might be all cracked I had a similar problem on my 77 silverado, turns out the heater box was full of pencils, pens, nails and a screwdriver. Don't store crap on the top of the dash __________________ Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life

11-25-2002, 01:25 AM	#6
mtdave2 newly minted old timer Join Date: Dec 1999 Location: Hudson WI Posts: 3,521	ya im sure its that door. it breaks right near the pivot pin. im even cheaper than you guys, i got 2 large washers and some really good epoxy. glued 1/2 the washer on the door and the other 1/2 on the part still connected to the pin.. works well. almost 2 years no trouble __________________ ____________________________________________ 72 c20 longhorn 65k org miles and counting! 69 k10 Suburban

11-25-2002, 10:22 AM	#8
johnnyp Keepin' It Stock Join Date: Aug 2001 Location: Grand Island, Nebraska, USA Posts: 554	Want a really cheap fix? Here's how the PO solved the problem. Works ok but it can be a little tricky to close or open while you're driving. I decided to go with a new box. Attached Images __________________ 72 Sierra Grande - Maych Forget about "do it right the first time". Do it wrong the first time to learn how, then do it right the second time.

11-24-2002, 02:37 PM	#3
DANL Senior Member Join Date: Mar 2002 Location: Bartlett, TN Posts: 348	Thanks Ack. ...Dan

11-24-2002, 11:41 PM	#5
DANL Senior Member Join Date: Mar 2002 Location: Bartlett, TN Posts: 348	Thanks Hooter! I plan to get into this weekend. ...Dan

11-25-2002, 09:48 AM	#7
DANL Senior Member Join Date: Mar 2002 Location: Bartlett, TN Posts: 348	Thanks MT. Looking forward to it not costing much. ...Dan

11-25-2002, 04:18 PM	#9
chevy2racr So Many Ideas, So Little Money Join Date: Sep 2001 Location: Marshalltown, IA Posts: 1,610	I was thinkin about doin somethign lke the last pic, but I'm not sure what you guys are sayin is broken. mine I took apart to replace the heatr core last winter and it didn't work whn I got it togeter, took it apart and pushed the flap up so it was in the heater vent direction. summer, I slide the lever and it goes back, took itapart this fall to flip it again, and just recently the defrost to heater changer stopped workin. I can move the slide but it stays at little on defrost, rest of heater(floor) any ideas? __________________ 72 Blazer 3/4 ton running gear 4.10s NP205/TH350 350 4in lift half doors 71 C10 with 454 99 S-10 5.1L SBC 700R4 09 Malibu Marshalltown, Iowa

11-25-2002, 11:49 PM	#10
chevy2racr So Many Ideas, So Little Money Join Date: Sep 2001 Location: Marshalltown, IA Posts: 1,610	ttt __________________ 72 Blazer 3/4 ton running gear 4.10s NP205/TH350 350 4in lift half doors 71 C10 with 454 99 S-10 5.1L SBC 700R4 09 Malibu Marshalltown, Iowa

11-26-2002, 01:31 AM	#11
DANL Senior Member Join Date: Mar 2002 Location: Bartlett, TN Posts: 348	That is deffinitely cheap Johnnyp. Chevy2racr I think my problem is with the first diverter controlled by the ac. ...Dan

11-29-2002, 04:09 PM	#12
chevy2racr So Many Ideas, So Little Money Join Date: Sep 2001 Location: Marshalltown, IA Posts: 1,610	any ideas for me to look for? __________________ 72 Blazer 3/4 ton running gear 4.10s NP205/TH350 350 4in lift half doors 71 C10 with 454 99 S-10 5.1L SBC 700R4 09 Malibu Marshalltown, Iowa

11-29-2002, 07:35 PM	#13
DANL Senior Member Join Date: Mar 2002 Location: Bartlett, TN Posts: 348	I am not an expert, and not sure I understand your problem, but it could be cable related. Is your cable moving diverter arm required distance? ...Dan

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