hvac heater bugs

[aaronR]

ok my only problem with my car when i first got it the heater fan switch would only work when it wanted to. after a while it quit. then about once a week it would kick on. (i always left it on pos 4 in case it would kick on so i would know). i never really got around to checking the problem yet i was gonna start by getting a new hvac pannel (the only thing that lights up on the pannel is the temp knob). well 2 nights in a row i was driving and i hit a decent sized pot hole and bam. the heater fan kicked on. possibly a loose ground?

oh and the car is a 90 325is if it matters

any opinions on where i should start?
thanks

[jlevie]

Start with the HVAC blower and work backwards to the fan speed switch.

[thedeal]

I have the same problem going on in my '90 325i. My HVAC is inop. unless i hit a pothole or slam my door really hard. I don't like going through these measures, nor should I. With the nasty NW fall weather well on its way I needed to fix this yesterday. Anyone else deal with this?

[thedeal]

P.S. yes I searched. That is how this thread was revived.

Garrett

[thedeal]

For anyone in the future interested in what happened... After digging into my bentley, (Ch. 15 Pg. 45) I decided to test my blower motor. It had power leading to it so the motor or components are obviously shot and I am searching for a new one now.

[Yakinho]

Did you check/clean the blower motor resistor?

[thedeal]

I did not bother. If the fan would have only run in the #4 position then I would have. Should I?

[Yakinho]

I'd check it just in case. It only takes about 5 mins. Mine usually only ran in 4th position, but later it got inconstant and wouldn't run at all. Ended up being the resistor.

[Huff]

In the 4th position, you aren't using the resistor.. So, if it works in 4th, you have a bad resistor.

[thedeal]

In the 4th position, you aren't using the resistor.. So, if it works in 4th, you have a bad resistor.

If the fan would have only run in the #4 position then I would have. Should I?

That is what I was trying to say here.

[///M42 sport]

so did you end up replacing the blower motor? I need to do the same. PITA or easy to do?

[thedeal]

so did you end up replacing the blower motor? I need to do the same. PITA or easy to do?

Not yet, I should recieve it here in a day or so. Getting to the motor ins't all that hard. After that I am unsure but the manual seems to make it seem pretty straight forward.

[thedeal]

so did you end up replacing the blower motor? I need to do the same. PITA or easy to do?

Recieved the motor tonight and put it in already. Easy as pie really. Nothing compared to my old honda. Twenty min. tops. The hardest part was removing the access panel, no shit. Good luck.