HELP PLEASE!!! Could it be my blower resistor???? - BMW Forum

ONE ILL740 · 06-14-2009, 07:47 PM

Hi,

This is my first time posting on a forum. I have a 1998 740il and am having a problem diagnosing my a/c problem.

Everytime i start the car the air seems to struggle to blow full blast for the first 15-20 mins. It seems to 'kick on' full blast after that. But if i turn the car off then on it takes another 15-20 mins. It consistently takes the same amount of time to blow hard. A mechanic friend told me that he thinks that if it WAS the blower resistor it would do the opposite...(blow hard at first and then die down after a while)

I don't want to take the time/money to replace the resistor if thats not the prob.
Any ideas out there?
Thanks in advance for any help you can offer.
Brad
520-240-2847

witeshark · 06-14-2009, 09:44 PM

It's very unlikely to be the fan resistor; they either work or not at all.

ONE ILL740 · 06-15-2009, 12:03 AM

Thanks for the reply.

Any ideas on what it could be???

witeshark · 06-15-2009, 12:06 AM

Circuit relays, or the climate CPU...

ONE ILL740 · 06-15-2009, 12:15 AM

Sounds like an easier fix than the resistor...

I'll start researching where those parts are and let you know if you're right.

Thanks for your time, I really appreciate all the help I can get for DIY projects on this car. (It's my first BMW, LOVE IT!!! Expensive as all get out to repair at the shop though)

ONE ILL740 · 06-15-2009, 12:21 AM

I really thought it might be the blower resistor because there are times when the a/c doesn't blow at all but if I slap my hand down on the dash a couple of times, it kicks on!!!??????????!!!!!!!!!!! Crazy, I know... but I was told that's where the resistor is

witeshark · 06-15-2009, 08:53 AM

It could be a bad connection, something loose.

Shoyoas · 06-29-2009, 09:46 AM

the resistor can be bad and it will still work sometimes. i don't think the resistor has a particular set of symptoms other than the fact that your blower will be "alive". it will work sometimes and not work at all sometimes. at least that the story on the 5 series and others on this site.

MARTYSX5 · 07-02-2009, 06:32 PM

I"d say 9 times outa 10 its the blower resister, when they act up its anything from only working at full speed to hitting the dash a slap to get it to wake up.