A/C not producing sufficient cold air - ZR-1 Net Registry Forums

mrzzzr1 · 09-23-2008

Have replaced the Electronic HVAC Controller with one my mechanic found on the west coast. GM original not available any longer. (Original controller was erratic a/c delayed for a period and also cut in and out whenever it felt like).
Have done 2-3 rechages the first two with dye and no leak detected although the feon was down ~.2 lbs. after a couple weeks.
Converted the old R-12 with new R-134a to reduce freon rechage cost.

Mechanic says he has done everything he can. Says the only thing left is there may be a pin hole leak in the evaporator core and he can't, or doesn't want, to fix it.

Have run the a/c for a couple months since with not much change. When it is hot I max out the temp at 60 and the fan on high and it barely keeps up.

A/C only seems to run on "AUTO" setting (is this they way it is supposed to work). When I run the outside air though the system (upr and lwr vents) without a/c it still seems to produce a/c sometimes (another bad HVAC controller).

Any ideas or suggestions are appreciated.

I think I have spent way too much time and money chasing this one.

-=Jeff=- · 09-23-2008

what is the volume of air out the vents like? the Evap gets pretty gummed up so the amount of air is reduced as well..

As for the AC Controller I have one from a 90, it was verified good in another Z owners car.. if you need it.

Sounds like a A/C programmer issue though

09-23-2008

You've got two components which people seem to confuse:

HVAC controller which is the dash unit
HVAC programmer which is just above the gas pedal

People call these the same thing sometimes. When you are not getting dash air control, it is usually the programmer and or the vent door assembly.

GOLDCYLON · 09-23-2008

AC will only run in AUTO unless you lower the fan speed from 10 Highest speed to a lower speed . You will notice then the green light above the auto will turn off but the AC still runs at the operators directed speed. I had a problem simular to this the AC would turn on when it wanted etc etc. Volume of air was great sometimes not so great other times. I ended up replacing the blower motor. A $40 fix and solved the intermitant problem. A fully functioning blower is critical and will cause suitcase/vent controller issues. Other than that a AC programmer above the footwell or a plugged evap as already stated. I would suggest the $40 fix first. The programmer is a bear to find. GC

-=Jeff=- · 09-23-2008

Quote:

Originally Posted by GOLDCYLON

The programmer is a bear to find. GC

Nah finding is easy.. getting under there to R&R that takes some work

GOLDCYLON · 09-23-2008

Quote:

Originally Posted by -=Jeff=-

Nah finding is easy.. getting under there to R&R that takes some work

Well thats true Jeff but I was refering to how hard it was to get the replacement part. R&R under there is a little more than a bear its a Bi--h

Unless your name is Jeffvette he lives for tight places.... LOL
And $1s $5 and $10 and dancing is involved

-=Jeff=- · 09-23-2008

Quote:

Originally Posted by GOLDCYLON

Well thats true Jeff but I was refering to how hard it was to get the replacement part. R&R under there is a little more than a bear its a Bi--h

yep, we are both ont he same page..

mrzzzr1 · 09-26-2008

Volume of air seems good and the blower seems to be doing its job. The temp of the air is not real cold though.

GOLDCYLON · 09-26-2008

Quote:

Originally Posted by mrzzzr1

Volume of air seems good and the blower seems to be doing its job. The temp of the air is not real cold though.

Ok then move onto the contoller

Aurora40 · 09-26-2008

You haven't actually said if the compressor cycles on?

09-23-2008	#1
mrzzzr1 Join Date: Jun 2004 Location: Mi Posts: 57	A/C not producing sufficient cold air Have replaced the Electronic HVAC Controller with one my mechanic found on the west coast. GM original not available any longer. (Original controller was erratic a/c delayed for a period and also cut in and out whenever it felt like). Have done 2-3 rechages the first two with dye and no leak detected although the feon was down ~.2 lbs. after a couple weeks. Converted the old R-12 with new R-134a to reduce freon rechage cost. Mechanic says he has done everything he can. Says the only thing left is there may be a pin hole leak in the evaporator core and he can't, or doesn't want, to fix it. Have run the a/c for a couple months since with not much change. When it is hot I max out the temp at 60 and the fan on high and it barely keeps up. A/C only seems to run on "AUTO" setting (is this they way it is supposed to work). When I run the outside air though the system (upr and lwr vents) without a/c it still seems to produce a/c sometimes (another bad HVAC controller). Any ideas or suggestions are appreciated. I think I have spent way too much time and money chasing this one. __________________ 1990 Red on Red vin #2433

09-23-2008	#2
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,136	Re: A/C not producing sufficient cold air what is the volume of air out the vents like? the Evap gets pretty gummed up so the amount of air is reduced as well.. As for the AC Controller I have one from a 90, it was verified good in another Z owners car.. if you need it. Sounds like a A/C programmer issue though __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - 3" Magnaflow Bullet cats - LT4 Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

09-23-2008	#3
Jeffvette Guest Posts: n/a	Re: A/C not producing sufficient cold air You've got two components which people seem to confuse: HVAC controller which is the dash unit HVAC programmer which is just above the gas pedal People call these the same thing sometimes. When you are not getting dash air control, it is usually the programmer and or the vent door assembly.

09-23-2008	#4
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,153	Re: A/C not producing sufficient cold air AC will only run in AUTO unless you lower the fan speed from 10 Highest speed to a lower speed . You will notice then the green light above the auto will turn off but the AC still runs at the operators directed speed. I had a problem simular to this the AC would turn on when it wanted etc etc. Volume of air was great sometimes not so great other times. I ended up replacing the blower motor. A $40 fix and solved the intermitant problem. A fully functioning blower is critical and will cause suitcase/vent controller issues. Other than that a AC programmer above the footwell or a plugged evap as already stated. I would suggest the $40 fix first. The programmer is a bear to find. GC __________________ 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 Last edited by GOLDCYLON; 09-23-2008 at 03:24 PM.

09-26-2008	#8
mrzzzr1 Join Date: Jun 2004 Location: Mi Posts: 57	Re: A/C not producing sufficient cold air Volume of air seems good and the blower seems to be doing its job. The temp of the air is not real cold though. __________________ 1990 Red on Red vin #2433

09-26-2008	#10
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,713	Re: A/C not producing sufficient cold air You haven't actually said if the compressor cycles on? __________________ Bob Saveland Former owner of #2517 [IMG]http://a.random-image.net/aurora40/vette.jpg[/img]