My AC blows 50-53 degrees in full sun and in the dark of night. My low side pressure is around 20psi. Haynes HVAC manual specifies 18-23psi for my maxima.

If the compressor didn't cycle off it would blow much colder because the temp drops fast while its running. But like clockwork it cycles off when the vent temp is 50.

Does anyone with colder air know their low side pressure? Could there be a sensor in the evaporator that is kicking the compressor off? I noticed some thingy with a wire going into the output side of the evaporator box.

 

I shall attempt to find out my pressure at work tomorrow. As for getting it cooler, I'm not that advanced YET but will be working on learning new stuff. I'm sure someone with more knowledge than I will contribute shortly. For now, be happy you at least get air cooler than 60 degrees

 

what's the pressure on the high side reading?
Also when you're taking the reading note the ambient temperature.

do you have auto or manual HVAC controls?

 

Insulate the cold line

 

I just have a cheap gauge from the parts store that can measure low side pressure, so I'm not sure about the high side.

Manual climate controls.

Ambient temp has been around 90, but I keep the car closed up. Cabin humidity sinks as low as 19% I'm really getting into this, bringing my meat thermometer into other people's cars, its becoming an obsession!

And I did insulate the cold line while I was living out west, its kind of ghetto with house pipe insulation wrapped over with insulating foam tape and coated with glue. Its very thick and nasty looking so I'm sure it helps.

I had the windows tinted today, 35% on the sides and 20% on the back window, and OMG, why didn't I do this 9 years ago?! Feels much cooler inside now. But I'm still determined to get 40 degree air coming out of my vents!

 

Amen to that, as soon as I find out how...I'll work on getting my AC blowing 45 degrees and BELOW although 47 degrees still gets me pretty cold to where I gotta lower the window or the fan speed.

 

I noticed that sometimes speed 1 can be too cold occasionally, or 2 would be too much when 1 is not enough. This gave me an idea to alter the controls to allow a slider for fan speed, instead of off and 4 steps. When I have more time, I'll try to find a manual control unit out of another car to tinker with, and see if I can get this working.

If you have one sitting around and would like to donate it for a potentially useful mod, that would be sweet

 

now figure out how that would work with the blower resistor.

i'm sure you can slap on a potentiometer and adjust fan speed that way. crack open your EE books

 

I want my mods list to include "Refrigerated Cabin"

 

eliminate the resistor with an adequate potentiometer. not my idea of safe though.

 

Honestly, I wouldn't mind that mod either <===refrigerant

 

potentiometer for speeds 1-4 + kill switch for the Off position, seems like it would work well.

What safety issue are you referring to? Starting a fire due to a high current, or something similar? If the blower is not taken above speed 4 then it should be fine. Isnt it on a fuse anyway?

 

yes I am refering to the high current.
high current = heat which can lead to fire/melting
the blower resistors are usually in the air stream to cool themselves off.

 

Mmm... yes... quite so.

I guess the potentiometer could be thermally coupled to that same resistor radiator, but obviously it wouldnt be within reach for easy speed adjustment. There are some possible workarounds for this issue, so all is not lost.

It wouldnt be worthwhile if it wasnt a challenge, I dont know of any car that has a continuously variable blower speed. This idea has been knocking around in the back of my head for a while, but I never evaluated it too seriously until right now.

 

a small fan blowing on it may work.
FWIW I think i still have a climate control head, without the slider floating around.

 

The stock resistors are right next to the fan, at the passengers feet. that'd be a stretch...

~Alex

 

My teacher/friend has a 2000 civic EX fully loaded (yes with 30k miles on it) and it has plenty of options for the fan, I think its got like 6-8 speeds IIRC, I was like "WOW!"

 

My friends 01 Civic has 12 different speeds.

 

His may have 12 as well.. who knows, I just know it was a shizzload

 

never said it was safe...but it's a way to adjust the power to the fan.
i never claimed to be EE expert nor i play one on TV.

best thing is to do the digital swap so whatever temp you want stays there.