defroster on 85 Silverado - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ges55 · 12-05-2012, 09:29 AM

I picked this truck up a couple of years ago. The defroster never has seemed to blow very hard. It was originally equipped with A/C, but it isn't currently hooked up. Could that be part of the reason it doesn't blow very hard or is that just the way these Squares are? My 67s' defrosters blow alot harder. Thanks.

INSIDIOUS '86 · 12-05-2012, 01:15 PM

Your blender door clip could be broke which is common, and maybe the motor is tired
Posted via Mobile Device
Also a/c trucks run vacuum hoses for the controls. Make sure the vacuum hose going out of the firewall is hooked up to the intake

ges55 · 12-05-2012, 03:28 PM

Thanks. Where is the clip located?

bnoon · 12-06-2012, 11:34 AM

Quote:

Originally Posted by ges55

Thanks. Where is the clip located?

This thread has the clip shown as part of a full heater box teardown. http://67-72chevytrucks.com/vboard/s...d.php?t=460942. Pretty easy to replace just the clip. Should be less than 10 minutes. http://www.gmpartsgiant.com/parts/gm...r-3018715.html for the clip currently priced at $1.63. Just got one myself about a week ago and now have full defrost.

motornut · 12-07-2012, 11:08 AM

the defrosters boxes i've seen apart also have an ajustment for the flow to the def/floor
inside
it gives a choice of always 1/3 up or down,or all up/down

f18delta · 12-07-2012, 12:52 PM

Insidious and bnoon are my new heroes!

Insidious for knowing what the name of the blender door clip was called. And bnoon for having the part number and link for it! Looks like I'll be pulling the box out again...

@Ges: I fixed my defroster air volume by undoing the screws on the one vacuum controller (that's either going or already gone on my 85) so that it doesn't allow any air to make it to the floor. The spring on the vacuum controller holds it in the down position quite well. The horizontal door that attaches to the bracket and threaded rod on the top are currently tied with 550 cord back to the passenger side of the dash to keep it open. I've got a couple of controllers to change out, but figured that I'd hold off until I figured out a way to replace the door clip. I had enough trouble with snapping one of the bolts that held the whole assembly to the firewall and didn't want to bother with it until I had to. Guess I've got a reason to now.

bnoon · 12-07-2012, 01:01 PM

I'm not a superhero, I'm just a man... with outstanding Google abilities... and laser eyes.

12-05-2012, 09:29 AM	#1
ges55 BLACK SATIN Join Date: Jan 2009 Location: canton, IL Posts: 266	defroster on 85 Silverado I picked this truck up a couple of years ago. The defroster never has seemed to blow very hard. It was originally equipped with A/C, but it isn't currently hooked up. Could that be part of the reason it doesn't blow very hard or is that just the way these Squares are? My 67s' defrosters blow alot harder. Thanks. __________________ 67 C10 Fleetside LWB-283, 3 on the tree,power assisted steering, father-in-law bought it new 67 C20 Fleetside LWB-'85 305 V8 (original was 250 6 cyl), Holley 600 carb, full length Hedman headers, dual exhaust behind the back wheels, 4 spd , manual steering 85 C10 Silverado- 305ci

12-05-2012, 01:15 PM	#2
INSIDIOUS '86 Registered User Join Date: Jul 2009 Location: washington Posts: 4,178	Re: defroster on 85 Silverado Your blender door clip could be broke which is common, and maybe the motor is tired Posted via Mobile Device Also a/c trucks run vacuum hoses for the controls. Make sure the vacuum hose going out of the firewall is hooked up to the intake __________________ 377 sbc thumpr cam autogear m23 muncie 3:73 Detroit trutrac 3''spintech prostreet mufflers xpipe 1 3/4 headers build thread !http://67-72chevytrucks.com/vboard/s...d.php?t=577217 Iroc gauge threadhttp://67-72chevytrucks.com/vboard/s...d.php?t=554511

12-05-2012, 03:28 PM	#3
ges55 BLACK SATIN Join Date: Jan 2009 Location: canton, IL Posts: 266	Re: defroster on 85 Silverado Thanks. Where is the clip located? __________________ 67 C10 Fleetside LWB-283, 3 on the tree,power assisted steering, father-in-law bought it new 67 C20 Fleetside LWB-'85 305 V8 (original was 250 6 cyl), Holley 600 carb, full length Hedman headers, dual exhaust behind the back wheels, 4 spd , manual steering 85 C10 Silverado- 305ci

12-07-2012, 11:08 AM	#5
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: defroster on 85 Silverado the defrosters boxes i've seen apart also have an ajustment for the flow to the def/floor inside it gives a choice of always 1/3 up or down,or all up/down __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350

12-07-2012, 12:52 PM	#6
f18delta Registered User Join Date: Sep 2012 Location: OKC, OK Posts: 82	Re: defroster on 85 Silverado Insidious and bnoon are my new heroes! Insidious for knowing what the name of the blender door clip was called. And bnoon for having the part number and link for it! Looks like I'll be pulling the box out again... @Ges: I fixed my defroster air volume by undoing the screws on the one vacuum controller (that's either going or already gone on my 85) so that it doesn't allow any air to make it to the floor. The spring on the vacuum controller holds it in the down position quite well. The horizontal door that attaches to the bracket and threaded rod on the top are currently tied with 550 cord back to the passenger side of the dash to keep it open. I've got a couple of controllers to change out, but figured that I'd hold off until I figured out a way to replace the door clip. I had enough trouble with snapping one of the bolts that held the whole assembly to the firewall and didn't want to bother with it until I had to. Guess I've got a reason to now. __________________ 1952 Chevy 3600 - Sancha

12-07-2012, 01:01 PM	#7
bnoon Registered User Join Date: Jul 2012 Location: Des Moines IA Posts: 1,250	Re: defroster on 85 Silverado I'm not a superhero, I'm just a man... with outstanding Google abilities... and laser eyes. __________________ - 1981 Sierra 454, NV4500 swap - 2006 Z06, 25k miles - 1973 Nova - Project CarNova Virus on Youtube



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