Thread: Aftermarket A/C - Blows cold, but doesnt cool off the car

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My 62 Fairlane has a Victory Climate Systems aftermarket air conditioner. I recently had the system serviced which included vacuuming out the system and recharging. I have three vents mounted below the dash. The air is cold blowing out but it never gets the car cool enough to have to turn down the fan on mid 80's degree day. Is there anything I should adjust, or is it simply not enough air flow to overcome all the glass in the car?

Originally Posted by Chicken Legs

My 62 Fairlane has a Victory Climate Systems aftermarket air conditioner. I recently had the system serviced which included vacuuming out the system and recharging. I have three vents mounted below the dash. The air is cold blowing out but it never gets the car cool enough to have to turn down the fan on mid 80's degree day. Is there anything I should adjust, or is it simply not enough air flow to overcome all the glass in the car?

How old is the system?
What was it charged with?
What is the temperature at the vents that is being blown into the cars interior?
Are your regular vents closed, or are you also allowing fresh (hot) air to flow into the car?



Bill S.

I'll add a few things to what Bill said.

What is the condition of your door seals? Air leaks will have a big affect on cooling.

What is the color of the car? Dark colors will add a lot of extra heat.

Does it start out blowing a lot of cold air and then drop off? The evaporator can freeze up when the charge is not quite right. Also, most of the aftermarket manufacturers I have seen do not recommend setting the thermostat to max cold to prevent the coil from icing over.

How much insulation is in the car? Older cars usually don't have much if any. Just the firewall can radiate a lot of heat that the AC has to deal with. This goes with what Bill said about the inlet temp of the air to the unit. If it's near the firewall, it could be having to cool very hot air.

How big is the condenser? If it was originally an R12 unit that has been converted to 134A, the condenser may be too small to reject all the heat. It was learned early when 134A started being used that the condenser needed to be at least 20% larger and/or much more efficient to get rid of the heat in the refrigerant. Look at new cars. They have very efficient cross flow condensers.

If it was an R12 unit that has been converted to 134A, the expansion valve should have been changed out for the higher pressure refrigerant.

How far is the condenser from the radiator? It needs to be spaced off the radiator about 1/2" to 1". No more. Too close and it picks up heat form the rad, too far away and it becomes a flow restriction for the whole cooling system.

I feel your pain, too. The Airtique(spelling?) AC in my black 46 coupe will just barely keep you from sweltering in really hot weather. The dark color and less than great insulation, as well as a weak AC unit are the culprits, I think. Will be getting the largest Vintage Air unit I can fit when I redo car. Along with lots of insulation.

System is about 10 years old, charged with R134a and recharged last week. Temp before having it checked was 47. Regular vents are closed. I also verified the heater core is closed.

Door seals have been replaced but still leak. Wind noise and after washing the car, I wipe out the water that splashes the interior. Red in color, both interior and exterior. It keeps blowing cold so its not freezing up. I'm unsure about how much insulation but I would tend to think its minimal. It may be as good as it gets.

put some gages on it. it may be off. remember too much is as bad as not enough with 134A . takes a lot of head pressure with it.

Some really good comments they covers most of the issues I've run into over the years on my and customer cars.

The one thing I'll add are the windows. If you have clear glass or even factory tint you have no UV protection. Even the lightest newer tints will provide that protection and can make a huge difference.

I personally have the lightest tint available on all but one of my cars and it really does help. The one that doesn't have the tint is an 87 Ram 50 pickup and the AC is sufficient to cool the small cab.



.

Here is something to check. I recently installed a new Vintage Air, generation 4 air conditioner in my 47 Chevy. It was blowing at 38 degrees, but I was not real happy with the volume of air it was blowing out. I checked the voltage at the blower with it running, and found that it was over two volts lower than the battery voltage. I ran a separate 12 gauge power wire from my battery cable into the car just to power the air conditioner, and used a relay triggered off the ignition switch to control it. Problem solved. It made a large improvement in the volume of cold air.

Also the quality of your fan at the condenser makes a big difference, especially when you are stuck at a stoplight. Adding a bigger fan, or building a shroud, or adding an extra pusher fan in front can really help.

I checked the voltage on the fan. Its 12 volts. The car has a nice fan shroud and electric fan. I had added a couple pusher fans in front of the condensor several months back to aid with cooling issues, should one come up. Only things left would be to check the pressure again, and add window tint. Thanks for the replies.

Originally Posted by Chicken Legs

I checked the voltage on the fan. Its 12 volts. The car has a nice fan shroud and electric fan. I had added a couple pusher fans in front of the condensor several months back to aid with cooling issues, should one come up.

With a quality electric fan properly shrouded to pull through the whole radiator area I believe that adding pusher fans will actually diminish your cooling by blocking air flow through a significant portion of your condenser area even when they're running, but especially when they are "off". Even if the blade were to freewheel (which it likely won't), they will still be blocking area with the frames. I'm not a fan of pusher fans unless they are the absolute last resort due to not having clearance to pull the air through the radiator & condenser. Just my $0.02 on electric fans.