Need Help with my A/C

[bryanallen_1]

Hi Guys,
I took my car to a tech to find out what the problem was with my A/C. It blows vent air but no A/C. When he held down the Climate control face to find out what codes it was throwing it said it was a "temp 21". Which he said was a sun sensor. In my mind the A/C should still work manually right? Both A/C techs told me that there was no leak in the system and it was holding pressure just fine. They also said that they were able to turn the A/C compressor from under the car manually. ??????? I am lost what should I do? Any ideas? Anything will help.

 

[sideshow]

it will bring up a code 21 sun sensor if u test for codes in the sun

u need to test for codes under shade or in the workshop

if he did check in workshop then it might be the sun sensor
it sits on top of dash
can u check what the outside or the inside cabin temp is on the a/c screen

check to see if it says a minus temp
had a prob with a nissan with faulty outside temp sensor
thought it was minus 51 degrees outside so therefore it would never turn on the a/c

 

[bryanallen_1]

More A/c questions...

Thanks for the reply... The tech did in fact check it in the shop. (shade). But what really fumbled me was that he said he would have to rip the dash out to get to the sun sensor. He wanted to charge $760 to do it and then told me it might not fix the problem. I am NOT fine with dumping that kind of money to find out that the problem is not fixed. In my mind, the A/C should work without the sun sensor. But I could be wrong. Do you know how to replace the sun sensor without ripping out the dash? if so I would love to do it my self. The part is only $50. The labor is $700.....LOL!

 

[bryanallen_1]

Well, I just went outside in to the garage (shade) and it gave me 3 seperate codes. It gave me Temp 21, Temp 33, and Temp 34. What could those be and what is my next step towards getting my air cold again. Thanks for all that reply.

 

[sideshow]

that is the great thing with mechanics
we are just like doctors
we buy these very expensive machines to tell us whats wrong
but at the end of the day we are still guessing

do a search on the net for those codes and see what u can find
as im not 100% sure if the sun sensor stops a/c from working

try speaking to afew more a/c technicians and see what they say

solving stuff that people never ever play with is very hard on these forums

at the end find someone who wants to charge you 700 bucks but is confident of fixing it

 

[bryanallen_1]

thanks sideshow...

Sideshow,
You rock. I found out that those codes indicate a inlet servomotor and a air mix servomotor can be shorted out or just flat out not working. How I get to them or what they look like is another thing. But I did hear from a tech that said the sun sensor is mostly just for the auto feature of the a/c system. I would love to put those servos in myself but there is a huge lack of info on how to do it.

 

[1uzvl]

Couldnt reply to your pm mate.

From what ive been told most sunlight sensor are for auto only and if you put it to cold/manual mode it should run as a normal system and from what ive been told only looking but not using the info from the sunlight sensor.

I would recomend having a look yourself to see if the a/c is actually working.Feel the large pipe from the firewall when the a/c is on it should be cold to touch.If it is from that vague test it will be the blend door servos not swapping from what you have said.

 

[bryanallen_1]

thanks....

Thanks for that info. I will give it a try and let you know. I really appreciate the helpful hints.

 

[bryanallen_1]

no nothing....

It seems as if when I turn the A/C to the on position, I don't hear or see the compressor turning on. I have a new climate control head unit and wonder if the compressor doesn't turn on, could it be the compressor or maybe just a signal to the compressor. All I got was codes for a servo motor, not a compressor. Any help with that one?

 

[stevechumo]

It seems as if when I turn the A/C to the on position, I don't hear or see the compressor turning on. I have a new climate control head unit and wonder if the compressor doesn't turn on, could it be the compressor or maybe just a signal to the compressor. All I got was codes for a servo motor, not a compressor. Any help with that one?

Check for the electrical plug on the A/C itself. The compressor should engage when you turn on the A/C on the climate control. Also, check all the fuses.

 

[1uzvl]

has your a/c worked before? have you just started to have dramas with it.

 

[bryanallen_1]

Will give it a go...

The A/C worked before. This is just an all of a sudden incident. I will check the connections to the A/C itself and all fuses. Hopefully something comes of it. Oh....and do you think it is possible that a "superheat sensor" can cause it to go bad? Thanks for all the helpful ideas.

 

[1uzvl]

its possible just as possible as anything else been a problem.Ive personally never seen one fail but not all compressors have them.

All else fails,jump the compressor straight to the battery using a fuse of course.There will be one single wire coming from the very front of the compressor,thats the wire you want.Start the car then connect to the +ve of thebattery,it should then run.Do the previous temp test i spoke earlier to see if its charged enough.

A low charge will not allow the system to start but it should be charged as you a/c tech have already verified this.

 

[sideshow]

code 21 is passenger solar sensor
code 21 might occur if testing is done in dark area even if all is normal

code 34 drivers maximum cool door position sensor circuit

still chasing what code 33 is

but this info is from my book for a 98 ls400

 

[sideshow]

when they turned compressor on manually does the air go cold
if so then the gas and pressure system is ok

u probably have a faulty climate control or air con ecu unit
what ever these cars have

these cars have so much crap behind the dash its major surgery to get to anything let alone test it

code 32 is air inlet door
so i guess code 33 will be similar