Mediocre A/C - Page 2 - ZR-1 Net Registry Forums

Corvette95 · 09-15-2023

So, I did the Haibeck mod back in 2020, very nominal improvement but my A/C does keep up here in Alabama on a 100 degree day but takes a while to cool off after sitting in the sun with windows up and glass top on (which is rare that it's parked anywhere). I had the heater box out anyway and found the foam insulation ALL around the heater box to firewall disintegrated to nothing. I could feel the air coming from around the firewall. I took high temp butyl tape all around the box to firewall and the line exiting the accumulator. Made a decent (not a breakthrough) increase in airflow. I am using OEM windshield BTW. I have been wandering if another GM blower would be a direct fit that has a high Air Flow per Minute? Thinking of GM SUV's....has anyone tried to find a higher flow direct fit blower motor?

Corvette95 · 09-15-2023

So, I did the Haibeck mod back in 2020, very nominal improvement but my A/C does keep up here in Alabama on a 100 degree day but takes a while to cool off after sitting in the sun with windows up and glass top on (which is rare that it's parked anywhere). I had the heater box out anyway and found the foam insulation ALL around the heater box to firewall disintegrated to nothing. I could feel the air coming from around the firewall. I took high temp butyl tape all around the box to firewall and the line exiting the accumulator. Made a decent (not a breakthrough) increase in airflow. I am using OEM windshield BTW. I have been wandering if another GM blower would be a direct fit that has a high Air Flow per Minute? Thinking of GM SUV's....has anyone tried to find a higher flow direct fit blower motor?

Neat · 10-23-2023

I didn't read the entire thread, apologies if I'm regurgitating something that's been said already:

I've noticed the AC on mine works great at first, but the blower motor slowly loses oomph over time. After an hour or so, I'd guess the AC output is 10% of what it was when I first started the car. If I turn off the car for awhile (stop and eat lunch / dinner) the AC returns to good performance, and then again degrades over the next hour or so.

I think my issue is the blower motor resistor warming over time, which (I think) is adding resistance over time, which is (I think) mimicking the driver commanding less air flow / blower speed. Eventually I'll rig a way to hotwire the blower motor to the "high" setting to check my theory.

If your issue is air output VS air temperature, the blower motor resistor might be worth considering.

09-15-2023	#11
Corvette95 Join Date: Jan 2006 Location: Decatur, AL Posts: 1,104	Re: Mediocre A/C So, I did the Haibeck mod back in 2020, very nominal improvement but my A/C does keep up here in Alabama on a 100 degree day but takes a while to cool off after sitting in the sun with windows up and glass top on (which is rare that it's parked anywhere). I had the heater box out anyway and found the foam insulation ALL around the heater box to firewall disintegrated to nothing. I could feel the air coming from around the firewall. I took high temp butyl tape all around the box to firewall and the line exiting the accumulator. Made a decent (not a breakthrough) increase in airflow. I am using OEM windshield BTW. I have been wandering if another GM blower would be a direct fit that has a high Air Flow per Minute? Thinking of GM SUV's....has anyone tried to find a higher flow direct fit blower motor? __________________ 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

09-15-2023	#12
Corvette95 Join Date: Jan 2006 Location: Decatur, AL Posts: 1,104	Re: Mediocre A/C So, I did the Haibeck mod back in 2020, very nominal improvement but my A/C does keep up here in Alabama on a 100 degree day but takes a while to cool off after sitting in the sun with windows up and glass top on (which is rare that it's parked anywhere). I had the heater box out anyway and found the foam insulation ALL around the heater box to firewall disintegrated to nothing. I could feel the air coming from around the firewall. I took high temp butyl tape all around the box to firewall and the line exiting the accumulator. Made a decent (not a breakthrough) increase in airflow. I am using OEM windshield BTW. I have been wandering if another GM blower would be a direct fit that has a high Air Flow per Minute? Thinking of GM SUV's....has anyone tried to find a higher flow direct fit blower motor? __________________ 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

10-23-2023	#13
Neat Join Date: Apr 2018 Location: Raleigh, NC Posts: 40	Re: Mediocre A/C I didn't read the entire thread, apologies if I'm regurgitating something that's been said already: I've noticed the AC on mine works great at first, but the blower motor slowly loses oomph over time. After an hour or so, I'd guess the AC output is 10% of what it was when I first started the car. If I turn off the car for awhile (stop and eat lunch / dinner) the AC returns to good performance, and then again degrades over the next hour or so. I think my issue is the blower motor resistor warming over time, which (I think) is adding resistance over time, which is (I think) mimicking the driver commanding less air flow / blower speed. Eventually I'll rig a way to hotwire the blower motor to the "high" setting to check my theory. If your issue is air output VS air temperature, the blower motor resistor might be worth considering. __________________ 1991 ZR-1 #769 - Turquoise / black - DRM 475 - 1993 Mustang - White / Black - Twin Turbos - Other Stuff - Last edited by Neat; 10-23-2023 at 07:57 AM. Reason: Grammar