air conditioning and radiator fans
#1
05-20-2009, 04:06 PM
air conditioning and radiator fans
***short version* A/C won't turn on, neither snowflake nor recirculator will stay lit, changed high pressure switch - no difference,
overheating - radiator fans won't turn on, temp needle doesn't go past middle line but temp light flashes when overheating. ***
I have an 1996 Audi A6 wagon and have had a couple of issues lately. A week or so ago, the air conditioning snowflake started to turn of by itself intermittently, and then blow hot air. If you tried to push the snowflake button, it would light up while you had your finger on it, only to go dark when you released it. After a few minutes, it would come back on by itself or would stay lit the next time you pushed it, only to repeat the problem a few minutes later. During this time it would blow cold when the snowflake actually came on. Within a day or so the snowflake wouldn't stay on at all and I got only hot air. I took it to a local VW shop and the guy said it sounded like an electrical problem, an charged me $85 just to run the diagnostic (argh - i though he was going to do an a/c test as well, but I got screwed), and came back with these codes:
Engine:
No fault code found
Readiness: N/A
Trans:
00526 Brake Light Switch-F
27-00 Implausible Signal
ABS Brakes:
65535 Internal Control Module Memory Error
35-00 - -
Auto HVAC:
01274 Air Flow Flap Positioning Motor(V71)
41-10 Blocked or No Voltage - Intermittent
00801 A/C Refrigerant High Pressure Switch (F118)
30-10 Open or Short to Plus - Intermittent
Airbags:
00532 Suppy Voltage B+
07-10 Signal too Low - Intermittent
Instruments:
No Faults Found
or DTCs not supported by controller
or a communication error occurred
So, he tells me I need a new high/low pressure switch and that the part is $155 plus labor. well, he had been recommended by someone so instead of doing any research I just told him to go ahead and order it, and took the car to work. On the way to work, I pushed the button, just to see what happened, and to my surprise it stayed on! But, also to my surprise, only hot air was blowing, even with the snowflake lit up. I called him and told him this but he said it didn't change anything about his diagnosis, even though I thought it should. So, I left it off and told him I would bring it on Tuesday (this was last Friday).
Monday comes along and I'm driving home from school (about 10 minute drive) when suddenly the temperature light starts flashing and smoke comes out from under the hood. It turns out that the smoke was just some coolant splashing on the engine or radiator and burning off, but when I pulled over there was a puddle of green coolant under the car. I think it bubbled over out of the reservoir.
I lost enough that what was left boiling in the reservoir was all sucked down into the radiator after waiting about 20 minutes for it to cool down. All this time the radiator fans didn't come on. I got more coolant, filled the reservoir and so far nothing has happened again, although I still haven't driven it more than ten minutes.
Tuesday I take it in to have him put the switch on, and tell him about the radiator. He asks is I want him to pressure test it and I, seeing another $85 "diagnostic", say no, but will he just check to see if he fan is coming on and what he might think the problem is - electrical, mechanical, etc. He says okay. Later he calls to say, "Oh, there's another problem. Your control head is bad - thats the heart of the whole system - $1200." Not surprised at this point because I feel like this guy is sticking it to me (total of $300 to replace the switch, including diagnostic), I act noncommital and tell him I'll be there in a minute to pick it up. When I arrive he says, "Good news, I found it used for $250." I ask him how he diagnosed the control head as the problem and he says, "I'm not sure, I'd have to ask the mechanic" and evades the question a couple of times.This is the guy with his name on the shop. So I ask him, "What about the radiator?" (It's even on the work order.) He stammers, goes to ask the mechanic, who says he didn't check it, and then goes outside to check it then. Revs the engine for 15 minutes to get it hot and then tells me, "Yep, the fan didn't come on."
Sorry about the novel, I just wanted to be sure I got all the pertinent info in. If someone could please help me try to diagnose this - my boyfriend (whose account this is) is handy and want to try to work on it, and he bought an obd tester so I don't get ripped off for $85 again. I definitely don't want to take it to that shop if the guy is ripping me off (list price for the part he charged me $155 for is $97.) Looking through archives the things I've seen for fan problems are FCM and a switch, also the coolant temp sensor. I'm wondering if the radiator and A/C problems could be related? It all kinda happened at once.
Thanks in advance
overheating - radiator fans won't turn on, temp needle doesn't go past middle line but temp light flashes when overheating. ***
I have an 1996 Audi A6 wagon and have had a couple of issues lately. A week or so ago, the air conditioning snowflake started to turn of by itself intermittently, and then blow hot air. If you tried to push the snowflake button, it would light up while you had your finger on it, only to go dark when you released it. After a few minutes, it would come back on by itself or would stay lit the next time you pushed it, only to repeat the problem a few minutes later. During this time it would blow cold when the snowflake actually came on. Within a day or so the snowflake wouldn't stay on at all and I got only hot air. I took it to a local VW shop and the guy said it sounded like an electrical problem, an charged me $85 just to run the diagnostic (argh - i though he was going to do an a/c test as well, but I got screwed), and came back with these codes:
Engine:
No fault code found
Readiness: N/A
Trans:
00526 Brake Light Switch-F
27-00 Implausible Signal
ABS Brakes:
65535 Internal Control Module Memory Error
35-00 - -
Auto HVAC:
01274 Air Flow Flap Positioning Motor(V71)
41-10 Blocked or No Voltage - Intermittent
00801 A/C Refrigerant High Pressure Switch (F118)
30-10 Open or Short to Plus - Intermittent
Airbags:
00532 Suppy Voltage B+
07-10 Signal too Low - Intermittent
Instruments:
No Faults Found
or DTCs not supported by controller
or a communication error occurred
So, he tells me I need a new high/low pressure switch and that the part is $155 plus labor. well, he had been recommended by someone so instead of doing any research I just told him to go ahead and order it, and took the car to work. On the way to work, I pushed the button, just to see what happened, and to my surprise it stayed on! But, also to my surprise, only hot air was blowing, even with the snowflake lit up. I called him and told him this but he said it didn't change anything about his diagnosis, even though I thought it should. So, I left it off and told him I would bring it on Tuesday (this was last Friday).
Monday comes along and I'm driving home from school (about 10 minute drive) when suddenly the temperature light starts flashing and smoke comes out from under the hood. It turns out that the smoke was just some coolant splashing on the engine or radiator and burning off, but when I pulled over there was a puddle of green coolant under the car. I think it bubbled over out of the reservoir.
I lost enough that what was left boiling in the reservoir was all sucked down into the radiator after waiting about 20 minutes for it to cool down. All this time the radiator fans didn't come on. I got more coolant, filled the reservoir and so far nothing has happened again, although I still haven't driven it more than ten minutes.
Tuesday I take it in to have him put the switch on, and tell him about the radiator. He asks is I want him to pressure test it and I, seeing another $85 "diagnostic", say no, but will he just check to see if he fan is coming on and what he might think the problem is - electrical, mechanical, etc. He says okay. Later he calls to say, "Oh, there's another problem. Your control head is bad - thats the heart of the whole system - $1200." Not surprised at this point because I feel like this guy is sticking it to me (total of $300 to replace the switch, including diagnostic), I act noncommital and tell him I'll be there in a minute to pick it up. When I arrive he says, "Good news, I found it used for $250." I ask him how he diagnosed the control head as the problem and he says, "I'm not sure, I'd have to ask the mechanic" and evades the question a couple of times.This is the guy with his name on the shop. So I ask him, "What about the radiator?" (It's even on the work order.) He stammers, goes to ask the mechanic, who says he didn't check it, and then goes outside to check it then. Revs the engine for 15 minutes to get it hot and then tells me, "Yep, the fan didn't come on."
Sorry about the novel, I just wanted to be sure I got all the pertinent info in. If someone could please help me try to diagnose this - my boyfriend (whose account this is) is handy and want to try to work on it, and he bought an obd tester so I don't get ripped off for $85 again. I definitely don't want to take it to that shop if the guy is ripping me off (list price for the part he charged me $155 for is $97.) Looking through archives the things I've seen for fan problems are FCM and a switch, also the coolant temp sensor. I'm wondering if the radiator and A/C problems could be related? It all kinda happened at once.
Thanks in advance
Last edited by Dan5; 05-21-2009 at 03:50 PM.
#2
05-20-2009, 10:37 PM
00801 A/C Refrigerant High Pressure Switch (F118)
30-10 Open or Short to Plus - Intermittent
I would have diagnosed this as being the problem as well, but it sounds like you have a refrigerant problem on top of that.
The electrical fan won't come on unless the A/C is on, since that doesn't work the fan will also not work. You have yourself a dumb *** mechanic..
Another thing about the coolant, there shouldn't be ANY green coolant in there. Thats antifreeze. If you are mixing antifreeze with the factory G-12 coolant it will gell up on you and overheat. You need to have that flushed out.
As for the A/C control head its possible, but if he hasn't even checked the high and low pressures, then he really hasn't done the diagnosis. I would keep the receipt from them, have a GOOD euro mechanic fix the car, and if his diagnosis is different, ask for a re-fund from the other shop and report them to the better business bereau.
30-10 Open or Short to Plus - Intermittent
I would have diagnosed this as being the problem as well, but it sounds like you have a refrigerant problem on top of that.
The electrical fan won't come on unless the A/C is on, since that doesn't work the fan will also not work. You have yourself a dumb *** mechanic..
Another thing about the coolant, there shouldn't be ANY green coolant in there. Thats antifreeze. If you are mixing antifreeze with the factory G-12 coolant it will gell up on you and overheat. You need to have that flushed out.
As for the A/C control head its possible, but if he hasn't even checked the high and low pressures, then he really hasn't done the diagnosis. I would keep the receipt from them, have a GOOD euro mechanic fix the car, and if his diagnosis is different, ask for a re-fund from the other shop and report them to the better business bereau.
#3
05-20-2009, 11:26 PM
thanks so much for responding. a couple more questions:
1. so at this point do we need a pressure test?
2. is any of this work we could do ourselves?
3. what do you think about the Fan Control Module possibly being bad (since the a/c clutch isn't engaging)?
4. should i get a new control head?
for coolant we are using just the peak antifreeze coolant (the manual says G 11 V8C but the previous owner had the green stuff in it already when i bought it 6 months ago.) is the flushing something we can do ourselves? is it important to have the other kind and would we need to order it?
thanks.
1. so at this point do we need a pressure test?
2. is any of this work we could do ourselves?
3. what do you think about the Fan Control Module possibly being bad (since the a/c clutch isn't engaging)?
4. should i get a new control head?
for coolant we are using just the peak antifreeze coolant (the manual says G 11 V8C but the previous owner had the green stuff in it already when i bought it 6 months ago.) is the flushing something we can do ourselves? is it important to have the other kind and would we need to order it?
thanks.
#4
05-21-2009, 02:44 AM
If you can't find a better price, ECSTuning sells the gallon for $ 21.74
You can surely do the flushing yourselves.
You can surely do the flushing yourselves.
#5
05-21-2009, 03:34 AM
for coolant we are using just the peak antifreeze coolant
Auditech has it right, you need to troubleshoot the actual A/C problem, and the High pressure Switch is where I'd start.
Then second place to look at is why the car overheated. They are most likely related.. as you prolly realized.
#6
05-21-2009, 08:24 AM
I'll doublecheck that coolant - I don't think it has silicates, but it is green.
He already changed the high pressure switch Tuesday and the A/C is still broken. Thats when he told me the control head was bad -(I'm assuming it wasn't bad on Friday when he first diagnosed the pressure switch). Could he have messed that up?
So I guess my next step is take it in for an A/C test? Is there any way I can confirm if the control head actually is bad?
Also, my temp gauge or thermostat or something must be bad, because it never went above the middle line. It was only the flashing temp light that signaled that it was overheating (that and the smoke
which thankfully only lasted a second.) And even after the car was cool, when I started it up to go get more coolant the light kept flashing until I filled the reservoir.
He already changed the high pressure switch Tuesday and the A/C is still broken. Thats when he told me the control head was bad -(I'm assuming it wasn't bad on Friday when he first diagnosed the pressure switch). Could he have messed that up?
So I guess my next step is take it in for an A/C test? Is there any way I can confirm if the control head actually is bad?
Also, my temp gauge or thermostat or something must be bad, because it never went above the middle line. It was only the flashing temp light that signaled that it was overheating (that and the smoke
which thankfully only lasted a second.) And even after the car was cool, when I started it up to go get more coolant the light kept flashing until I filled the reservoir.
Last edited by Dan5; 05-21-2009 at 11:14 AM.
#7
05-21-2009, 02:20 PM
update
Well, after running fine for the last 3 days, it overheated again today after driving for 15 minutes. It was hotter out today than it had been earlier this week, though. Once again the needle never rose above halfway, but the temp light started flashing. The coolant level was fine, and not boiling this time) so I let it cool for 30 minutes and drove it home. The light was no longer flashing when I started it and didn't come on again. Obviously there is a problem with my gauge as well.
I guess I need to worry more about the overheating than the A/C. Couldn't they both be related to the radiator fans not coming on and the A/C clutch not engaging? If so, where do I start? An A/C test isn't going to find the overheating problem, right? So, troubleshoot the electrical system to see if the fans are getting power?
One other thing, there is a green 2 pin/prong/hole? connector that isn't connected to anything hanging near the radiator on the driver's side. Is this just extra or for an accessory I don't have?
I guess I need to worry more about the overheating than the A/C. Couldn't they both be related to the radiator fans not coming on and the A/C clutch not engaging? If so, where do I start? An A/C test isn't going to find the overheating problem, right? So, troubleshoot the electrical system to see if the fans are getting power?
One other thing, there is a green 2 pin/prong/hole? connector that isn't connected to anything hanging near the radiator on the driver's side. Is this just extra or for an accessory I don't have?
#8
05-21-2009, 08:07 PM
Couldn't they both be related to the radiator fans not coming on and the A/C clutch not engaging?
So, troubleshoot the electrical system to see if the fans are getting power?
It was only the flashing temp light that signaled that it was overheating (that and the smoke which thankfully only lasted a second.) And even after the car was cool, when I started it up to go get more coolant the light kept flashing until I filled the reservoir....
...Once again the needle never rose above halfway, but the temp light started flashing.
...Once again the needle never rose above halfway, but the temp light started flashing.
PM me your e-mail.. I'll send you a couple things that could help trace things out. You have the 2.8 V6 correct?
#9
05-21-2009, 10:03 PM
coolant level light?
the light that comes on is the flashing thermometer - i'm not sure if its the coolant level light or not. i don't think so because the coolant level was fine this time.
the first time it overheated (monday) it did lose alot of coolant and the light kept flashing even after it cooled off - until i refilled the coolant, then it stopped. this time the coolant wasn't boiling or low, and after waiting 30 minutes the light stayed off when i started it back up to drive 5 minutes home.
also, when the guy revved it up to see if the fans would come on, he said it got to around 102 degrees and the fan still didn't come on.
the first time it overheated (monday) it did lose alot of coolant and the light kept flashing even after it cooled off - until i refilled the coolant, then it stopped. this time the coolant wasn't boiling or low, and after waiting 30 minutes the light stayed off when i started it back up to drive 5 minutes home.
also, when the guy revved it up to see if the fans would come on, he said it got to around 102 degrees and the fan still didn't come on.
Last edited by Dan5; 05-21-2009 at 10:07 PM.
#10
05-22-2009, 12:20 PM
The flashing thermometer is low coolant level.
The other problems listed as intermintent might be due to a poor ground. I'd remove the chassie to motor strap (bottom front right side of motor) clean all surfaces and replace it.
Next I would look at the refigerant pressure... I think you can access it thru the heater control pannel but don't have the info with me. Refilling the 96 A6 wagon AC requires a special fitting because there is no low pressure schrader valve like other vehicles.
I'd also start looking for a water leak... If it is not obvious you'll probably find it at the back of the motor or from the thermostat. If it is the thermostat you might as well do the Timing belt etc.
The other problems listed as intermintent might be due to a poor ground. I'd remove the chassie to motor strap (bottom front right side of motor) clean all surfaces and replace it.
Next I would look at the refigerant pressure... I think you can access it thru the heater control pannel but don't have the info with me. Refilling the 96 A6 wagon AC requires a special fitting because there is no low pressure schrader valve like other vehicles.
I'd also start looking for a water leak... If it is not obvious you'll probably find it at the back of the motor or from the thermostat. If it is the thermostat you might as well do the Timing belt etc.