# AC problem - Audi 100



## 95025 (Nov 14, 2010)

First things first...

It is very likely that you're low on refrigerant - low enough that there's not enough pressure in the system, and it won't allow the AC Compressor to engage.

For about $25 you can get a can of refrigerant, including the hose and connector for the low pressure port on your AC System. http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_R-134a-EZ-Chill-13-oz--R-134a-Refrigerant-Plus-Oil-and-Leak-Sealer-Interdynamics_7010212-P_N3572_T|GRP2004A_____

With the engine running, and AC on high, shoot a can of that in there and see if it builds enough pressure to let the Compressor engage.


Beyond that, honestly, if you're not a serious DIY mechanic, I'd take it to a professional. The AC systems can get pretty complicated.


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## Rehabber (Dec 29, 2005)

DrHicks said:


> First things first...
> 
> 
> For about $25 you can get a can of refrigerant, including the hose and connector for the low pressure port on your AC System. http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_R-134a-EZ-Chill-13-oz--R-134a-Refrigerant-Plus-Oil-and-Leak-Sealer-Interdynamics_7010212-P_N3572_T|GRP2004A_____
> ...


 Your system was originally charged with R12 refrigerant. Unless it has been converted to R134a, DO NOT add R134a.


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## 95025 (Nov 14, 2010)

Rehabber said:


> Your system was originally charged with R12 refrigerant. Unless it has been converted to R134a, DO NOT add R134a.


Good point. Of course, if it has NOT been converted, he won't be able to add 134a without the adapter kit.


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## PPang100 (Jul 21, 2011)

*91 Audi 100*

Everyone, I told you wrong about the model year of my Audi 100. It's a 91 instead of the stated 89. The car has been converted to the R134a system. I didn't think about checking if the freon was low enough to prevent the AC from coming on. I will have the shop check that out.

My car died on me today again. It was like 97 degree outside, and I was driving and stopping doing errands. Suddenly, the engine went dead. tried cranking several times but failed. Disconnected the fuel line and checked the fuel pump. It was good. There is spark in the coil wire. Speedometer not working, now comes on and off, more off's than on's. After 40 minutes, could start the car again, No more than1/8 mile, the engine died the second time. Same thing, after about 30 minutes, the engine died again. What's going no? Car had to be towed to garage.

Please help.


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## PPang100 (Jul 21, 2011)

DrHicks said:


> First things first...
> 
> It is very likely that you're low on refrigerant - low enough that there's not enough pressure in the system, and it won't allow the AC Compressor to engage.
> 
> ...



I am curious, when I turn on "ECON", it's supposed to have the fan to come on, but the fan doesn't come on. If AC is turned on, then I would expect the AC to come on. But why doesn't eh fan come on?


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## Thurman (Feb 9, 2009)

"The fan doesn't come on"----key words here. With the ignition switch in the "ON" position, motor not running, and the fan_ does not_ come on//and: IF the motor is running, you turn the fan "ON" to any fan speed setting and the fan _does not _come on: You may have a bad fan resistor. This is what sets your fan speed. Let's say you have a three or four speed fan, then you will have resistors for two or three of the fan speeds. The full fan speed does not need/nor have a resistor. IF one of these resistors has blown, then on some model cars, your A/C system will not come on. It's safety thing. I would have the resistor checked at this time. On a '91 Audi they may be able to diagnosis this with a computer hook-up. Now with the car in the shop for the "dying" problem it would be a good time to have them check it out. Good Luck on the "dying" problem


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## PPang100 (Jul 21, 2011)

Thurman said:


> "The fan doesn't come on"----key words here. With the ignition switch in the "ON" position, motor not running, and the fan_ does not_ come on//and: IF the motor is running, you turn the fan "ON" to any fan speed setting and the fan _does not _come on: You may have a bad fan resistor. This is what sets your fan speed. Let's say you have a three or four speed fan, then you will have resistors for two or three of the fan speeds. The full fan speed does not need/nor have a resistor. IF one of these resistors has blown, then on some model cars, your A/C system will not come on. It's safety thing. I would have the resistor checked at this time. On a '91 Audi they may be able to diagnosis this with a computer hook-up. Now with the car in the shop for the "dying" problem it would be a good time to have them check it out. Good Luck on the "dying" problem



That's really good information. Thank you. I will have to mention this to the shop to check the fan resisters. I will have them check the freo level, too.


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## PPang100 (Jul 21, 2011)

Thurman said:


> "The fan doesn't come on"----key words here. With the ignition switch in the "ON" position, motor not running, and the fan_ does not_ come on//and: IF the motor is running, you turn the fan "ON" to any fan speed setting and the fan _does not _come on: You may have a bad fan resistor. This is what sets your fan speed. Let's say you have a three or four speed fan, then you will have resistors for two or three of the fan speeds. The full fan speed does not need/nor have a resistor. IF one of these resistors has blown, then on some model cars, your A/C system will not come on. It's safety thing. I would have the resistor checked at this time. On a '91 Audi they may be able to diagnosis this with a computer hook-up. Now with the car in the shop for the "dying" problem it would be a good time to have them check it out. Good Luck on the "dying" problem


On the dying problem, something weird is going on. I was able to drive the car off the garage after the mechanic kept my car for a couple week and did nothing. I managed to drive the car off the garage, and I am into my third week driving w/o a hiccup. This is weird. Any idea anyone?


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## ukrkoz (Dec 31, 2010)

yes. it is weird. stop worrying and keep driving. don't worry if it ain't brok, if it's brok, don't worry but fix it right away. 
it's just a car. marry someone, you'll have more things to really worry about.


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## PPang100 (Jul 21, 2011)

ukrkoz said:


> yes. it is weird. stop worrying and keep driving. don't worry if it ain't brok, if it's brok, don't worry but fix it right away.
> it's just a car. marry someone, you'll have more things to really worry about.



Ukrkoz, I like your advice. I will keep on trucking until the problem comes back. I hope never. But, I have to get the AC fixed.

Sounds like you are discouraging me to get married. So getting married will give me more things to worry about? I could pass my problems to her and let her take care of them.

Thanks, happy motoring.


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## picflight (Aug 25, 2011)

Audi, late mid eighties through early ninety, nothing but troubles. You really have to be a hands person to drive and own one.


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## ukrkoz (Dec 31, 2010)

PPang100 said:


> Ukrkoz, I like your advice. I will keep on trucking until the problem comes back. I hope never. But, I have to get the AC fixed.
> 
> Sounds like you are discouraging me to get married. So getting married will give me more things to worry about? I could pass my problems to her and let her take care of them.
> 
> Thanks, happy motoring.



there's a huge prize for a first man that will get pregnant.

there should be another one, larger one, for a first man that will win it with a woman.


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