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Discussion Starter #1
It's summer time and it's in California and my Alfa's AC isn't at best condition.

Q1. Is engine cooling fan suppose to be turning when AC is on (Auto mode, temp set to LO )

Sympton is that the compressor seems to be doing it's job. I am getting pressure/vacuum from high/low pressure side, and the guage used to check pressure indicates good amount of R134a. No bubble seen at the glass viewing window.

But... no cold air coming out...

Q2. Is there anything else I can check before sending it to the shop?

ps. engine fan does run when needed to cool engine coolant.
pss. I am not able to use the self-diag of the climate controller because the lcd display is pretty much gone...

Thanks!

Jess
 

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Q1 Engine fan designed to come on low speed with A/C on when high side freon pressure reaches about 215 psi. The trinary switch on receiver dryer makes and grounds cooling fan low speed relay if low speed resister in cooling fan shroud is good then cooling fan runs until pressure drops back to about 180 psi.

Do fan run on low speed when engine coolant about 198F or is it only coming on high speed about 206+?

If you are pulling vac on low side of compressor Freon level to low and compressor clutch should be disengaging.

Q2 If you truly have enough freon and correct pressures and compressor engages and you still get hot air you need to verify temp stepper motor and temp door lever are working. Look down below passenger wiper arm pivot point behind blower moter and see if black lever with wire control cable attached moves all the way forward when temp set to low and back to cabin firewall when temp raised to hot.
 

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Discussion Starter #3
Thanks Steve!

Unfortunately, my mechanic bypassed low speed temp sensor atop radiator to make the fan run at full speed ( disconnected from the temp sensor, and on the ecu side, the connector has been jump'ed together. ) so i won't be able to tell

So I am not too sure if that changes anything in terms of AC functionality. However, after that was done, the AC did work well for a year.

I walked to the parking, opened the hood and pulled the plastic cover to look for the lever but w/o success. I will try again tonight with better lighting.

Thanks!

Jess
 

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Thanks Steve!

Unfortunately, my mechanic bypassed low speed temp sensor atop radiator to make the fan run at full speed ( disconnected from the temp sensor, and on the ecu side, the connector has been jump'ed together. ) so i won't be able to tell

So I am not too sure if that changes anything in terms of AC functionality. However, after that was done, the AC did work well for a year.

I walked to the parking, opened the hood and pulled the plastic cover to look for the lever but w/o success. I will try again tonight with better lighting.

Thanks!

Jess
As long as fan runs on high when low speed switch in radiator or trinary switch in a/c is made that is fine.

You will need a bright flash light you can focus like a mag light to see if arm moves and is not broken etc.
 

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Thanks Steve!

Unfortunately, my mechanic bypassed low speed temp sensor atop radiator to make the fan run at full speed ( disconnected from the temp sensor, and on the ecu side, the connector has been jump'ed together. ) so i won't be able to tell

So I am not too sure if that changes anything in terms of AC functionality. However, after that was done, the AC did work well for a year.

I walked to the parking, opened the hood and pulled the plastic cover to look for the lever but w/o success. I will try again tonight with better lighting.

Thanks!

Jess
I suggest hooking it all back up as it was intended. mechanic's bypass the low speed and just mask the problem.
You need the low speed. Not only so that it runs while the A/C is no but all so that it does not wear out the fan motor. It is better for the motor to go from the slow to the high instead of straight to the high. In this set up as well the fan does not stay on long enough. With both speeds you get a longer duration of the fan which = cooler temps.
If you your A/C is good check the lever inside the panel behind the glove box. wire is connected up high to a white plastic arm. Moving that back and forth gives you hot cold or mixed air. Also check the wire lever inside the engine compartment behind the false fire wall as that can sometime slip off if there is no speed clips, same with inside the car.
I suspect that is your problem as Steve mentions.

Good luck let us know what you find. Need pictures let me know and I can shoot some unless someone has them already?
J
 

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Discussion Starter #6
Hi Jason, yeah, I understand the need of 2 speed setup... eventually it will get there... engine and mechanics are P1, AC and niceties P2 :)

I did verify that the lever do move properly. When set to LO, or cool, the arm is fully extended (lever closer to engine) and when set to HI or hot, the arm retract and lever is closer to firewall.

So.. sounds like I need to go back to check the freon pressure again and monitor coolant temperature. Maybe I didn't do it right the first time. Last time I checked, the compressor clutch was engaging, but last 2 days I don't hear that anymore.

I'll report as I make more progress.

BTW, for those following this thread, the lever is to the left side of the air box behind the blower motor housing when looking at the engine bay in front of the car. A copper colored thin rod extended from behind the firewall to activate the lever. It's easier spot'ed standing at the passenger side. Obviously the thin plastic shield has to be removed to see.
 

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Discussion Starter #7
You won't believe what I found out...

Turned out that the guage was the culprit. It gaves irratic readings.. so when it showed good pressure range, it was meaningless.

I gave it a small shot of R134a and immediate the compressor kicked in! So I gave it half a bottle (don't know proper capacity and don't want to over charge it). Today's pretty cool so can't really say how well it worked but it does cool now enough that I had to turn ac off as i drove home from work.

So I guess that's it, a bad guage tricked me into thinking I had good freon pressure when I didn't have any... and spend days reading the manuals trying to figure out what else could cause the sympton :)

Thanks Steve!! Thanks Jason!!!! :)


jess
 
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