AC went out, Please help me locate Fuse and Relay

Hello TDI lowers, I'm one of those, and i'm going nuts, because my AC went out. Not Because I can drive witout it, cuz of my wife and others that driving with me.

Please help me locate fuse and relay for AC.

and other possible ways to check why it went out.

Many thanks to all who can help...

i just checked fans, and they all work fine... Its just "Cold Air" is not coming out..
All the fuses are good and everything is intact..
Is it possible for Relay under the steering wheel to go bad?? Buz when I press "AC" button, nothing triggers like it used to be...

Thanks...

one guy also told me,

QUOTE " if there is no enough R134a your AC will not work "
I was wondering , will this might be what he said???

i just might have not enought R134a???

Thanks

When you say "all fans" do you mean that both radiator/condenser fans come on when you turn on the AC?
Does the cabin fan also blow? On all speeds?
Does the AC button light up?
Does the AC compressor clutch engage? (Does the inside of the pulley start turning?)
On the A4 there is no relay under the dash for the AC.

It is true that if there is not enough refrigerant, the system will not work. That is true of every refrigerant system in the world.

If there is not enough refrigerant in your system, then the fans will not come on and the clutch will not engage. Hence the question about the fans.

Please try to be exact and complete in your information. Details are very important.

DanG144 said:

When you say "all fans" do you mean that both radiator/condenser fans come on when you turn on the AC?
Does the cabin fan also blow? On all speeds?
Does the AC button light up?
Does the AC compressor clutch engage? (Does the inside of the pulley start turning?)
On the A4 there is no relay under the dash for the AC.

Click to expand...

1) Both, Radiator /condenser fans are working
2) Cabin fan works fine too, an all 4 speeds
3) A/C button also ON
4) A/C clutch is not engaging... i used to hear engine starding to worm massivly and something clicks (probably when AC compressor clutch engage) , but not anymore.

ok, It was like working yesterday on my way home, but very next day, I started engine, just to gain Water temperature to 100F before i leave the house and get car ready , so I turned A/C on, and left car, but when I came back in like 3-5 mini, It was warme then when I left.... Thats how It happened....

Since both radiator fans come (on in slow?) when you turn on the AC, then it is not:
low refrigerant pressure.
the fan voltage interlock.
the outside temperature switch interlock.
loss of control signal to the FCM (Fan Control Module).

It could be:
clutch coil burned out.
bad clutch wiring.
Fan Control Module bad.
High refrigerant pressure interlock (though your fans should be in fast speed if this was the case- note that this is normally due to a bad high pressure sensor, unless you have been adding refrigerant.)
Lockout of the clutch by the ECU due to high engine load signal or high temperature signal.

I would start by checking the AC compressor clutch coil resistance. It should be about 4 ohms. And making sure it is plugged in. Look to ensure the rodents have not chewed up the wiring to the compressor.

it was not slow speed, I totally dropped this.. Its was fast speed...

what would be the easyest thing to do??

Are the fans coming on in fast even without the AC being turned on? Just with the key on and AC off?

If your fans are running in fast speed, and you have not added any refrigerant, then it is likely to be a bad high pressure sensor. They cost about $70, I think. There are other potential causes, that involve engine temperature sensors failing, wiring, and fan control modules failing.

If you are not going to do the troubleshooting in the thread I referred you to earlier, then I would try to find an A4 owner to swap out HP sensors with, to see if that fixed it.

But first, try this.

Unplug the HP sensor electrically. Do your fans turn off?

i'll check that on wed, and will let you know...
HP sensor.. (where would it be) can U please explain??

Thanks

The high pressure transducer is by the firewall, right side. It looks like a small canister with a three wire connector on it. It's on the aluminum refrigerant line.

If the A/C worked intermittently, it may just be a bad fan controller. Unplugging the sensor will help isolate the components. If the fans turn off, the sensor can be replaced without losing refrigerant.

thanks Jcrews, I have day off on wed, so I'll check all that.
Thanks you all guys who's trying to help me and for your advces...
I'LL KEEP YOU GUYS POSTED..

jcrews said:

The high pressure transducer is by the firewall, right side. It looks like a small canister with a three wire connector on it. It's on the aluminum refrigerant line.

If the A/C worked intermittently, it may just be a bad fan controller. Unplugging the sensor will help isolate the components. If the fans turn off, the sensor can be replaced without losing refrigerant.

Click to expand...

I removed that wire from HP sensor, and fans went off right away...

DanG144 said:

If you are not going to do the troubleshooting in the thread I referred you to earlier, then I would try to find an A4 owner to swap out HP sensors with, to see if that fixed it.

Click to expand...

I was wodering how to remove that sensor from A/C like?? so I can try to swtch it with one of my friends Jettas..

plus fuses 5 16 25 and 164 are good...

That sensor simply unscrews. There is a schrader valve (like a tire valve stem) that keeps you from losing too much refrigerant. Just unscrew it rapidly and completely once you start unscrewing it.

Since the fans stopped when you unplugged it, it is almost sure to be a bad sensor.
Unless you added some refrigerant.

no, I havent add any refrigerant. So just remove wiring to it, and just unscrew it regularly, or it has special counterclockwise ???
Will refrigetant squirt at me?? or not?

just use wrench to unscrew it?? (showed in pink)

That is right. Apply counter torque to the mounting pipe so you do not bend any tubing.

Thanks, I'll switch it on Friday afternoon with my buddy's one.. And will keep you posted...

Just In case, i was browsinf Inet for sensor, Will this be It http://www.autoanything.com/relays-sensors-switches-74-960/201A3942.aspx?N=4294966685+4294966625

or I there are other switches or dfferent prises??

Thanks

You might read the part number off of the one you remove. I would look at this one for a replacement.

http://www.idparts.com/catalog/product_info.php?products_id=1918
A/C High Low Pressure Switch (Late A4)
[a4_late_highlow_switch] $35.95
.OE Part Number: 1K0959126A
Manufacturer's Part Number: 1J0959126