A/C Questions

Hello -

After being able to get the heater going on in my car, it is not time figure out how to cool the car...

Now that the summer heat is almost here, I need help with my A/C system. I have the Auto Climate feature in my car btw...

Some issues I have an idea what is causing it, others, I don't so I am hoping to rely on you guys.

1. Lo fan speed non-functional - blower resistor?
2. Anytime I try to turn on the fan, it seems that my A/C compressor kicks in because my RPM goes down (happens even when I'm on heat function) - confirmed that the relay and A/C clutch is functional. Compressor do kick in when I turn on the fan...
3. A/C button not lighting up - can this be due to faulty light, bad solder connection, or something else in the system (no gas, compressor failure?)
4. When I initially bought the car, there was some sort of toggle switch wired to the battery and to the A/C compressor harness that didn't make a difference when I flip the switch... I now have disconnected this and seen nothing different... At first I thought the A/C Compressor was hardwired but this may not be the case.
5. What/where is the common leak source for the A/C line? I remember on my 91 MR2 (SW20), there was a rectangular (o-ring) rubber that needs to be replaced on the compressor (i believe it was in the manifold) which is always the culprit for A/C leak... how about for the st162?

Thanks!

 

How can i possibly solve the A/C Compressor not to turn on when it should not? Any suggestions?
oh and how do I trouble shoot the automatic climate control for the car? When I press the auto button on the A/C control panel, no air blows out...

 

Hey, Thanks..

But yeah, when I press the Auto A/C, no air is coming out... the fan is not working... I know this cuz' I can't hear my fan blower... same thing when I press the Lo button... I re-soldered the panel when I did the heater fix...

As for the A/C button, the button does not light up at all... When I press/de-press, nothing happens... the compressor is always engaged... I verified this by physically inspecting the compressor in the engine bay.. the only way I can disengage the compressor is if I pull the relay out... other than that, each time I run the fan, the compressor is engaged even if I have it on heat...

I did unclip the valve near the firewall that controls the hot/cold temp... i do get heat, but I don't get any cold... I kinked the cable that push/pull the valve so I just left it unclipped...

Could it be the blower resistor causing the Auto function to not blow any air since the Lo fan button does not work as well?

Where do I start in figuring out what causes my compressor to always be engaged???
I will try to re-solder everything again and see... Could this be a case of bad soldering point on the HVAC panel and the compressor is stuck in the "on" function?

 

will update the thread once I get to work on it this week... BTW, when I say auto function, nothing works when both the fan/air direction light is on... meaning if i choose the full-auto function...

but when I have the fan on high plus press the auto function for the air vent directions, it works fine... but still not getting as cold

 

is this so?? all along i was thinking that it also should control the fan, hence it has two lights and a picture of fan and air direction respectively...

 

Mine is slightly different. It has both the direction and fan.

 

According to the dealer sticker i have for the car, this was an option added.

 

I drove the car yesterday and my wife wanted to ride along and asked to turn on the A/C... I told her it is not blowing any cold air but she insisted to turn it on... to my surprise, the A/C blew cold air... I observed closely if there was a difference when I'm constantly moving to when I am at a full stop/idle and it seems that there was no significant change... the air blowing was constant...

I don't know how this happened but I am hoping that the A/C is "miraculously fixed"... as for the compressor always "on," I still have not worked on it... I will first try to re-solder the controls again and see if that will make a difference... Other than bad control, what else can cause the compressor to always kick in?

 

i tried to just push/pull the cable and spray some wd40... other than that, i have not really tried to follow the cable line and check whats behind the dash...

 

so i my wife and i somewhat cleaned the car so I was able to ask her to help me out with the A/C... here's is what i found out...
when i change the slider to hot, the cable in the firewall move all the way in.... when the slider is set to cold, the cable doesd not move at all and i need to pull it out... as i pull it out, i do not feel any kind of resistance...

as for my A/C compressor, it still kicks in regardless if im on heat or cold... when i disconnected the wire to the compressor, the clutch did not engage... my relay is working im sure about that...

the only thing i haven't done yet it to resolder the HVAC panel again... i'll probably do it tomorrow.... in the likelihood that it is not the HVAC panel, what else could be the culrpit??? the clutch itself? pressure switch???

 

i finally was able to open up the hvac panel and re-solder again... i also took the liberty to observe the behavior of the cable when the temp is changed to hot/cold....

the motor is definitely working.... i think the main issue is that when i put the temp slider to cold, the cable flexes instead of being pushed out... thus, the other end is not able to push the heater valve in the firewall.... i'll post the video i took to show this...
https://www.youtube.com/watch?v=8k9DkOT7y2Q&feature=youtube_gdata_player


for the A/C compressor always kicking in, re-soldered everything... nothing changed... the A/C compressor still kicks in each time is turn the fan on... the A/C button light does not work, and even if i swapped another bulb, the light still does not turn on... there was one thing i noticed though.. if you look into the picture below, it seems that there is a bare/exposed line on the circuit board... could this be the culprit why the A/C compressor is always "on"?

 

This morning I decided to re-check my relay and the fuse box and this is what I found out...




I sit normal that the relay socket/hold only has three lines/wires? Or do you suspect that somebody tampered it and hard wired the A/C compressor to always be on?