C3 Vent Airflow -- A/C
Thread Starter
Heel & Toe
Joined: Apr 2002
Posts: 15
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From: Atlanta GA
C3 Vent Airflow -- A/C
Found this on alt.autos.corvette awhile ago and figured I'd save it for the day when I get my vette. I'm not sure if it has appeard here before but I figured I'd post it to get it in the archives and to help out the people with A/C problems, especially with the summer heatwave comming.
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OK, guys someone put this in the archive of C3 a/c dsicussions, as I will not
type this again...
first off, take the system completely apart, and clean out all the leaves from
the evap housing....this is a must do...
second, take that silly ground wire off the blower frame and toss it, solder a heavy 10 ga wire to the cleaned up tab on the motor housing, then solder another end on it directly tied to the engine....move the hi speed relay off the evaporator housing over the headers where it tends to over heat and burn up after a while...
skin back the wires and solder to the original relay tabs, ensuring a great
connection....
the thick orange high speed wire is about 10 ga...it goes to the dedicated
inline white housed fuse hear the horn relay/distribution point....make sure
that fuse housing is new or at best proven good.....
with blower on high speed now...measure with a digital volt meter directly
across the blower motor...it should say same as alternator output...about
13.5-14.4 some volts, while running on high speed....
replace blower motor if needed, probably need one, cheap anyway....
make sure that damn connector at the motor itself is good, I seen them corrode and melt the + terminal of the blower motor....bad connection....
if you have a 68-72 vette this next step is a pain in the butt, but still must be done on any shark.....get at that silly blower trap door up under the
passenger's fender, down the wiper well...there are 3 5/16ths screws holding that damn door in place....
pull them and the door out of there, disconnect the spring loaded vac cannister and that allows the door to flap freely.....run a screw through the plastic door, and wrap a 12" length of solid electric wire around the screw head securely.... remount door, wrapping other end of wire around any handy screw to hold that damn door shut permanently.....
use a screwdriver to put RTV all around the door edges this ensures no rain, dirt, leaves ever get into the system again....take out any dirt screens from this area, as they are not longer needed.....
inside the pass kick panel take the inner flapper door out, ans toss it....
block all vac lines to missing vac cannisters.....obviously....
now the system is on recirculatiing air only......with max airflow....
obviously a valve of some sort is needed in the heater water circuit, preferably on both sides.....as the engine water will heat that core anyway.... just osmosis....
make sure the heater flapper door is all the way shut when commanded.....
insulate hell out of the firewall and make damn sure there are NO holes allowing engine compartment heat into the car interior.....
insulate under the carpets....and tranny tunnel....
I used fiberglass 1/2 thick, with aluminum backing foil form hardware store for this insulation job...good as anything, better than most....forget the 'kits' mostly they are NOT enough.....miss too much....
obviously a good charge of freon is necessary with out leaks.....
in my car there was a largish aluminum air deflector pivoted in a housing near the center console.....I took it out,....maximised the airflow.....
if the blower motor does not see full alternator output on the high speed, the wiring must be replaced, and no more than .4 volt drop allowed.....and even that is high, IMO....
GENE
--
HOME OF THE BUY-TRONIC VETTE....
WE CAN MODIFY IT, WE HAVE THE TECH......
http://home.att.net/~ncmpics/mrvette.htm
---------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------
OK, guys someone put this in the archive of C3 a/c dsicussions, as I will not
type this again...
first off, take the system completely apart, and clean out all the leaves from
the evap housing....this is a must do...
second, take that silly ground wire off the blower frame and toss it, solder a heavy 10 ga wire to the cleaned up tab on the motor housing, then solder another end on it directly tied to the engine....move the hi speed relay off the evaporator housing over the headers where it tends to over heat and burn up after a while...
skin back the wires and solder to the original relay tabs, ensuring a great
connection....
the thick orange high speed wire is about 10 ga...it goes to the dedicated
inline white housed fuse hear the horn relay/distribution point....make sure
that fuse housing is new or at best proven good.....
with blower on high speed now...measure with a digital volt meter directly
across the blower motor...it should say same as alternator output...about
13.5-14.4 some volts, while running on high speed....
replace blower motor if needed, probably need one, cheap anyway....
make sure that damn connector at the motor itself is good, I seen them corrode and melt the + terminal of the blower motor....bad connection....
if you have a 68-72 vette this next step is a pain in the butt, but still must be done on any shark.....get at that silly blower trap door up under the
passenger's fender, down the wiper well...there are 3 5/16ths screws holding that damn door in place....
pull them and the door out of there, disconnect the spring loaded vac cannister and that allows the door to flap freely.....run a screw through the plastic door, and wrap a 12" length of solid electric wire around the screw head securely.... remount door, wrapping other end of wire around any handy screw to hold that damn door shut permanently.....
use a screwdriver to put RTV all around the door edges this ensures no rain, dirt, leaves ever get into the system again....take out any dirt screens from this area, as they are not longer needed.....
inside the pass kick panel take the inner flapper door out, ans toss it....
block all vac lines to missing vac cannisters.....obviously....
now the system is on recirculatiing air only......with max airflow....
obviously a valve of some sort is needed in the heater water circuit, preferably on both sides.....as the engine water will heat that core anyway.... just osmosis....
make sure the heater flapper door is all the way shut when commanded.....
insulate hell out of the firewall and make damn sure there are NO holes allowing engine compartment heat into the car interior.....
insulate under the carpets....and tranny tunnel....
I used fiberglass 1/2 thick, with aluminum backing foil form hardware store for this insulation job...good as anything, better than most....forget the 'kits' mostly they are NOT enough.....miss too much....
obviously a good charge of freon is necessary with out leaks.....
in my car there was a largish aluminum air deflector pivoted in a housing near the center console.....I took it out,....maximised the airflow.....
if the blower motor does not see full alternator output on the high speed, the wiring must be replaced, and no more than .4 volt drop allowed.....and even that is high, IMO....
GENE
--
HOME OF THE BUY-TRONIC VETTE....
WE CAN MODIFY IT, WE HAVE THE TECH......
http://home.att.net/~ncmpics/mrvette.htm
---------------------------------------------------------------------------------------
