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#1 |
Join Date: Mar 2021
Location: Crawfordville, FL
Posts: 216
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I have a '90 ZR-1 which has developed a problem that I have researched on here and on the Corvette Forum and Googled and have yet to find a solution to, without ripping the whole interior of the car apart. I have cold AC, I have control over the vents (so I must have vacuum), I have control over the blower speed, but the airflow out of the vents is very poor. Setting the fan on "10" has the fan running at top speed but has the airflow I would expect out of "2". I have removed the blower motor and the evaporator is perfectly clean as is everything else I can see in there. I removed the blower motor controller to look into the other side of the evaporator and that area and as far as I can see is also clean in there. I attached a suction hose to my shop vac and sucked up in there as far as I could go, and nothing came out. I also put it up into the heater vents in the interior of the car and got nothing out. There must be a mouse or other rodent's nest in the ducts somewhere or total deterioration of the small amount of foam sealing the ducts, but where do I look next? Is there anyway to access the main duct system without removing everything under the passenger side dash, and if I did that, would I find where the problem is? I would hate to take that all apart and not find the problem.
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#2 |
Join Date: Mar 2021
Location: Crawfordville, FL
Posts: 216
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I found part of the problem. I removed the grates over the center and passenger dash vents and got a good look in there. There were fragments of 30 year old foam which I sucked out with the shop vac and blew into there with the vac on blower, alternating a couple of times. I wouldn't say that totally fixed the problem but it made it a lot better - I can actually feel air blowing on my face now, much more than before. So I doubt I have a rodent's nest in there, it's just partially blocked with old deteriorated dried out GM foam.
The 12V feed to the blower motor itself and to the speed controller both seem normal, at 13.9V with the engine running, so I don't think there's a problem there. I am trying to upload a short video of the fan motor running but I can't figure out how to do it here. It's not silent, possibly is making a low volume whistling/whining or scraping noise. While it works, maybe at 30 years old it's tired and needs replacing for more oomph. Maybe if I take it out again I could lube it but that would probably be a temporary fix. Before digging into the interior and dash, I may invest $25-30 on a new blower motor to see if that helps even more. |
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#3 |
![]() ![]() ![]() Join Date: May 2007
Location: Peoria, AZ
Posts: 9,154
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https://www.zr1.net/forum/showthread...ghlight=colder
Replace the 30 plus year old blower motor and while you are there block the vertical gap if it exists ![]()
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GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director ![]() 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V |
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#4 |
Join Date: Mar 2021
Location: Crawfordville, FL
Posts: 216
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The other thing about the foam is, I have no idea if that comes from the sealing of the various doors to direct the airflow, or if it comes from where the ducts join to one another, where, if that is the case, there could possibly be air leaks out of those areas into below the dash, resulting in poor airflow out of the vent outlets.
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#5 |
![]() Join Date: Jan 2006
Location: Decatur, AL
Posts: 1,112
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When I had the heater box out on mine, all the foam surrounding the firewall was deteriorated. When I re-installed I used Butyl tape all around the split cases and firewall. It helped mine, plus new blower and Haibeck mod.
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Corvette95 Registry and Forum (*************) 1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD 1995 C4 Coupe Purple/Blk 6 Speed 1989 C4 Conv Wht/Red Auto SOLD 1996 C4 Conv Black/Tan Auto SOLD 1994 C4 Coupe Wht/Blk SOLD 1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD 1986 C4 Coupe Black/Red 4+3 SOLD 1990 C4 ZR-1 Red/Red #0454 |
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