[Big Busa]

Just like it says, purchased a new aux fan but it is still not coming on. Still having air con issues. While driving, she blows cold air. Sitting at a light, she starts blowing warm air and then once i start driving again, it gets colder. The dealer told me that i needed a new fan so i got one. Not at their $829 rate but i got it. Still having the same issue. I searched but could not find anything like this.

Anyone got any ideas?

[Big Busa]

By the way, no cel, no over heating issues that shows up.

[Pr335bob]

Idk if this helps. But my car would go warm randomly. Turns out I had a leak / small hole in a ac line. Check for leakage it saved me aprox 600$ .All the guy did was weld that hole with aluminum good as new. Try to Do a leak test any reputable ac tech can do it it doesn't have to be a BMW guy. I know your problem is different but try it if you haven't already. That's Always The Best Way To Start When Dealing With A probs.

[turbs]

If you had an ac leak then you would eventually have no gas left to cool the air so not sure if it could be that. I would say it sounds like a heater matrix issue or possibly even a thermostat problem.

[Big Busa]

Should have said that I just changed my wp and thermostat. My main issue is why won't my new aux fan come on when the ac is on? Really getting worried she is not cooling right but no cel so I can't really tell.

[Gizm0]

Do you have any "ghost" codes that won't trigger a CEL? I had a fan related code a few weeks ago, but it didnt trigger the CEL. I was however able to read it with my JB4. My radiator fan decided to quit working for a day... Next day, everything was back to normal. Strange problem!

[j1gilles]

Originally Posted by Big Busa

Just like it says, purchased a new aux fan but it is still not coming on. Still having air con issues. While driving, she blows cold air. Sitting at a light, she starts blowing warm air and then once i start driving again, it gets colder. The dealer told me that i needed a new fan so i got one. Not at their $829 rate but i got it. Still having the same issue. I searched but could not find anything like this.

Anyone got any ideas?

Check A/C pressure at idle once the air turns warm.. I bet it is low. As you drive your A/C compressor spins faster thus compressing the R134 "more"... The aux fan will not activate if pressure drops past a certain psi. You probably have a slight leak somewhere. Buy one can of R134 at Autozone and send me 5 dollars for fixing your issue jk... Good luck!

[Big Busa]

Originally Posted by j1gilles

Check A/C pressure at idle once the air turns warm.. I bet it is low. As you drive your A/C compressor spins faster thus compressing the R134 "more"... The aux fan will not activate if pressure drops past a certain psi. You probably have a slight leak somewhere. Buy one can of R134 at Autozone and send me 5 dollars for fixing your issue jk... Good luck!

Ha!! Thanks for the heads up! Will check tomorrow morning. Just back in the country! If, if that is the problem, I will send you half!

[j1gilles]

Good luck!

[mankytron]

It is not cooling while sitting still because there is no air flow across the condenser. Your ac seems to be working if it is cooling on the highway, so doubt you have a leak. I would look for a fan relay or module problem.

[Big Busa]

Originally Posted by mankytron

It is not cooling while sitting still because there is no air flow across the condenser. Your ac seems to be working if it is cooling on the highway, so doubt you have a leak. I would look for a fan relay or module problem.

ok... maybe i am just slow but i have been searching but cannot find a fan relay/module to change out. is it directly on the fan? if so, can it be removed and changed? can you help me locate it so i can check it out?

[Jeff@TopGearSolutions]

Originally Posted by mankytron

It is not cooling while sitting still because there is no air flow across the condenser. Your ac seems to be working if it is cooling on the highway, so doubt you have a leak. I would look for a fan relay or module problem.

First thing I thought of is Relay/Fuse/Module.

Originally Posted by Big Busa

ok... maybe i am just slow but i have been searching but cannot find a fan relay/module to change out. is it directly on the fan? if so, can it be removed and changed? can you help me locate it so i can check it out?

Check the fuse box for items related to A/C or check google for diagram.

[j1gilles]

I would just throw in a can of R134... 12 dollars at AutoZone.

[Big Busa]

Originally Posted by Jeff@TopGearSolutions

First thing I thought of is Relay/Fuse/Module.



Check the fuse box for items related to A/C or check google for diagram.

So, it turned out to be my fuse! Stealership tried hard to get me to spend $800 to replace my fan and it was a $4 part that was the problem! Had I just paid what they wanted, I would have been out $796 bucks!

[j1gilles]

Go get your diag fee back

[Jeff@TopGearSolutions]

Originally Posted by Big Busa

So, it turned out to be my fuse! Stealership tried hard to get me to spend $800 to replace my fan and it was a $4 part that was the problem! Had I just paid what they wanted, I would have been out $796 bucks!

It's always the simple stuff. Gotta start with the basics