Cooling Fan switching on/off too quickly when running AC
 

95 GTI VR6 with 140K miles and "running" strong except - yesterday temps
were in the 90's and in traffic my AC started making a growling noise then
shut down and then turned on after a few seconds then off. After car
started moving turned system back on - quickly cooled no problems. During
idle high speed fan will turn on for a few seconds then switch off and then
cycle again. Took the car to an AC specialist - but not VW specialist and
said pressures were fine but he did notice the fan switching on and off
which could if the outside temps were high enough could cause the system to
get too high of pressure and shut down the system since the fan isn't really
cooling down the coil. Ok, but what would fix the problem - radiator
switch, switch located on the thermostat housing or is it the Fan Control
Module?
Is there a way to test the Fan Control Module?

here in the uk it is a common fault of the golfs that the fan internal
resistor blows preventing the fans from operating properly. VW are aware of
the fault. Suggest yours may be similar. Do some research...you may get it
do under goodwill from VW

That's a multi speed fan and you need to check the speeds first. With the AC
on the fan should run at low speed. as temps go up it will jump to the 2nd
speed. If it sounds like a jet engine, then it's on the 3rd speed.


"S Timinski" > wrote in message
m...
> 95 GTI VR6 with 140K miles and "running" strong except - yesterday temps
> were in the 90's and in traffic my AC started making a growling noise then
> shut down and then turned on after a few seconds then off. After car
> started moving turned system back on - quickly cooled no problems. During
> idle high speed fan will turn on for a few seconds then switch off and
> then cycle again. Took the car to an AC specialist - but not VW
> specialist and said pressures were fine but he did notice the fan
> switching on and off which could if the outside temps were high enough
> could cause the system to get too high of pressure and shut down the
> system since the fan isn't really cooling down the coil. Ok, but what
> would fix the problem - radiator switch, switch located on the thermostat
> housing or is it the Fan Control Module?
> Is there a way to test the Fan Control Module?
>
>
>

Tried jumping the AC pressure switch (fan portion) and it will turn on the
fan - but I don't think I'm getting the third speed. Tried jumping
connectors at the radiator and I get the fan to go but it doesn't sound like
a "jet engine" just fast. Is there any way to force the third speed?


"Woodchuck" > wrote in message
...
> That's a multi speed fan and you need to check the speeds first. With the
> AC on the fan should run at low speed. as temps go up it will jump to the
> 2nd speed. If it sounds like a jet engine, then it's on the 3rd speed.
>
>
> "S Timinski" > wrote in message
> m...
>> 95 GTI VR6 with 140K miles and "running" strong except - yesterday temps
>> were in the 90's and in traffic my AC started making a growling noise
>> then shut down and then turned on after a few seconds then off. After
>> car started moving turned system back on - quickly cooled no problems.
>> During idle high speed fan will turn on for a few seconds then switch off
>> and then cycle again. Took the car to an AC specialist - but not VW
>> specialist and said pressures were fine but he did notice the fan
>> switching on and off which could if the outside temps were high enough
>> could cause the system to get too high of pressure and shut down the
>> system since the fan isn't really cooling down the coil. Ok, but what
>> would fix the problem - radiator switch, switch located on the thermostat
>> housing or is it the Fan Control Module?
>> Is there a way to test the Fan Control Module?
>>
>>
>>
>
>

Don't think I'm getting into the third speed - low speed seems fine - and I
think its running in second - but I cant seem to get it in third. Is the
function of running on third part of the Fan Control Module or the fan unit
itself? Is there a way to jumper it to the third setting bypassing the
control module? Also when I took it to an A/C place they said the Fan
Control seemed like it was "clicking" - but since he wasn't a VW specialist
he couldn't give a proper diagnosis on the electrical. When the temps are
in the 70 or low 80's and driving normally the temp readings get and stay at
about 37-38 under normal load so i think the AC portion
(compressor/condensor/evap and expansion valve) is working. Ordered a Fan
Control Module from the dealer using the recall part code which cost about
60 dollars versus the 200 that they would normally charge - found that info
on VWVORTEX and the kit is normall for the Corrado SLC but others have tried
it and it works unmodified for 95 and later GTI VR6's. Ordered it because I
don't think my after run fans seem to be working as well. Any info on the
third speed would be helpful. Thanks in advance.

"Woodchuck" > wrote in message
...
> That's a multi speed fan and you need to check the speeds first. With the
> AC on the fan should run at low speed. as temps go up it will jump to the
> 2nd speed. If it sounds like a jet engine, then it's on the 3rd speed.
>
>
> "S Timinski" > wrote in message
> m...
>> 95 GTI VR6 with 140K miles and "running" strong except - yesterday temps
>> were in the 90's and in traffic my AC started making a growling noise
>> then shut down and then turned on after a few seconds then off. After
>> car started moving turned system back on - quickly cooled no problems.
>> During idle high speed fan will turn on for a few seconds then switch off
>> and then cycle again. Took the car to an AC specialist - but not VW
>> specialist and said pressures were fine but he did notice the fan
>> switching on and off which could if the outside temps were high enough
>> could cause the system to get too high of pressure and shut down the
>> system since the fan isn't really cooling down the coil. Ok, but what
>> would fix the problem - radiator switch, switch located on the thermostat
>> housing or is it the Fan Control Module?
>> Is there a way to test the Fan Control Module?
>>
>>
>>
>
>

Well, jumpered the connector on the BROWN sensor at the thermostat and
definately got the highest speed fan. And I did notice that the fan was
switching on but not superspeed and the relay seemed to be clicking - so I'm
assuming that the BROWN sensor is most likely shot. Whats a little strange
is that the afterrun fan doesn't appear to be working either - so maybe the
control unit is gone as well.
"Woodchuck" > wrote in message
...
> That's a multi speed fan and you need to check the speeds first. With the
> AC on the fan should run at low speed. as temps go up it will jump to the
> 2nd speed. If it sounds like a jet engine, then it's on the 3rd speed.
>
>
> "S Timinski" > wrote in message
> m...
>> 95 GTI VR6 with 140K miles and "running" strong except - yesterday temps
>> were in the 90's and in traffic my AC started making a growling noise
>> then shut down and then turned on after a few seconds then off. After
>> car started moving turned system back on - quickly cooled no problems.
>> During idle high speed fan will turn on for a few seconds then switch off
>> and then cycle again. Took the car to an AC specialist - but not VW
>> specialist and said pressures were fine but he did notice the fan
>> switching on and off which could if the outside temps were high enough
>> could cause the system to get too high of pressure and shut down the
>> system since the fan isn't really cooling down the coil. Ok, but what
>> would fix the problem - radiator switch, switch located on the thermostat
>> housing or is it the Fan Control Module?
>> Is there a way to test the Fan Control Module?
>>
>>
>>
>
>

The only time the fan goes to 3rd speed is by last resort to save the engine
from atomic melt down if speeds 1 & 2 are dead. The 3rd speed may come on if
you are driving through "Death Valley" but I wouldn't know because it's one
place on earth I don't want be be in.


"News" > wrote in message
. ..
> Well, jumpered the connector on the BROWN sensor at the thermostat and
> definately got the highest speed fan. And I did notice that the fan was
> switching on but not superspeed and the relay seemed to be clicking - so
> I'm assuming that the BROWN sensor is most likely shot. Whats a little
> strange is that the afterrun fan doesn't appear to be working either - so
> maybe the control unit is gone as well.
> "Woodchuck" > wrote in message
> ...
>> That's a multi speed fan and you need to check the speeds first. With the
>> AC on the fan should run at low speed. as temps go up it will jump to the
>> 2nd speed. If it sounds like a jet engine, then it's on the 3rd speed.
>>
>>
>> "S Timinski" > wrote in message
>> m...
>>> 95 GTI VR6 with 140K miles and "running" strong except - yesterday temps
>>> were in the 90's and in traffic my AC started making a growling noise
>>> then shut down and then turned on after a few seconds then off. After
>>> car started moving turned system back on - quickly cooled no problems.
>>> During idle high speed fan will turn on for a few seconds then switch
>>> off and then cycle again. Took the car to an AC specialist - but not VW
>>> specialist and said pressures were fine but he did notice the fan
>>> switching on and off which could if the outside temps were high enough
>>> could cause the system to get too high of pressure and shut down the
>>> system since the fan isn't really cooling down the coil. Ok, but what
>>> would fix the problem - radiator switch, switch located on the
>>> thermostat housing or is it the Fan Control Module?
>>> Is there a way to test the Fan Control Module?
>>>
>>>
>>>
>>
>>
>
>

Will first replace the Fan Control Module which is on order and then the
brown thermalswitch, since the fan does cycle on and off every few seconds
when in idle and AC is on so that I can go back to the A/C place if it cuts
out again so that the electrical possibilities are ruled out. Think the
system is running only in the first fan speed and intermitently will jump
and drop out quickly from the second speed. Whats really bugging me is why
the compressor is making noise after about a year like it struggling and
then when the car is cool from start or if the temps outside are down it
works fine - no noise. I don't want to mess up the compressor since its
basically new as are the expansion valve and dryer.
"Woodchuck" > wrote in message
...
> The only time the fan goes to 3rd speed is by last resort to save the
> engine from atomic melt down if speeds 1 & 2 are dead. The 3rd speed may
> come on if you are driving through "Death Valley" but I wouldn't know
> because it's one place on earth I don't want be be in.
>
>
> "News" > wrote in message
> . ..
>> Well, jumpered the connector on the BROWN sensor at the thermostat and
>> definately got the highest speed fan. And I did notice that the fan was
>> switching on but not superspeed and the relay seemed to be clicking - so
>> I'm assuming that the BROWN sensor is most likely shot. Whats a little
>> strange is that the afterrun fan doesn't appear to be working either - so
>> maybe the control unit is gone as well.
>> "Woodchuck" > wrote in message
>> ...
>>> That's a multi speed fan and you need to check the speeds first. With
>>> the AC on the fan should run at low speed. as temps go up it will jump
>>> to the 2nd speed. If it sounds like a jet engine, then it's on the 3rd
>>> speed.
>>>
>>>
>>> "S Timinski" > wrote in message
>>> m...
>>>> 95 GTI VR6 with 140K miles and "running" strong except - yesterday
>>>> temps were in the 90's and in traffic my AC started making a growling
>>>> noise then shut down and then turned on after a few seconds then off.
>>>> After car started moving turned system back on - quickly cooled no
>>>> problems. During idle high speed fan will turn on for a few seconds
>>>> then switch off and then cycle again. Took the car to an AC
>>>> specialist - but not VW specialist and said pressures were fine but he
>>>> did notice the fan switching on and off which could if the outside
>>>> temps were high enough could cause the system to get too high of
>>>> pressure and shut down the system since the fan isn't really cooling
>>>> down the coil. Ok, but what would fix the problem - radiator switch,
>>>> switch located on the thermostat housing or is it the Fan Control
>>>> Module?
>>>> Is there a way to test the Fan Control Module?
>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>