Help! stumped by HVAC problems.

[Richard Oben]

Ok, let me see if anyone can help me. My wife has an 02 X5 we (I) do most of the work on it. Oil changes, brakes, etc. She loves it and like all high mile X5s it has had the front end rebuilt, CVs done and the oil water seperator redo done typical X5 stuff. And yes it uses about a quart of oil every 3k miles. Still in nice shape so we do want to keep it at least for now, if this problem persists I will sell it and get something else.

This spring the blower quit working so I got on here and learned (great site for info and DIY stuff) about the problems and put a FSR in it and it worked for a couple of months. While I was out of town it quit again in June. Wife went to the shop we know and trust, they have been ok so far no complaints except the cost. When she got there they put a different FSR in it and it worked about a block. Their diagnosis was a blower motor. So they put the 3 month old FSR back in and it worked. So when I get back in town one of my buddies put a blower motor in it. Not a DIY generally, about 8 hours or more worth of work, really a pain. Remove the whole dash! Cleaned every contact and put dielectric grease on any thing electric that needed it or not. Neither of us were convinced there was anything wrong with the blower. The experts said that is what is was. Now, I do not mind putting a blower in a 9 year old car with 130K on it. It was not that expensive compared to a car payment. So a new FSR and a new blower all in the last 4 months.

So now here I am about 3 weeks later and the HVAC quits again, blower motor does nothing. Just for giggles I put a brand new from BMW dealer FSR in it (I get a discount because of my business) No change! The compressor will turn on and the aux fan will spin but not for long as the blower not working gets the evap pretty cool pretty fast and without the interior fan it turns off pretty fast. Neither of them have anything to do with the blower fan inside the car as far as I know. If I turn the AC off the vent fan will not blow.

So what does the group think. The shop can not take it until Monday and we have other cars to drive. One is another BMW 94 325is that will not die, 175K and the AC works great, go figure no leaks original clutch and still fun to drive.

I just really want to fix this once and for all. Thanks in advance for any ideas, good bad or anything that may or may not work. If I can fix it before Monday it will save me money compared to the labor at the shop. Richard.

[Zulu95]

"put dielectric grease on any thing electric that needed it or not"
Just a quick FYI: Dielectric grease is an insulator.

[Richard Oben]

We put non corrosive silicon grease designed for contacts on all the contacts to and put it on all the grounds as a lubricant and corrosion preventer. We are aware that it in an isulator, used on plug wires etc. We cleaned all the contacts and to avoid any further issue we greased them. This was done after all the contacts were verified to work. Just a preventive measure.

Anyone have anything else? Richard.

[Weasel]

Would take some poking around with a voltmeter when it is acting up to see where the power path stops... Basically checking the power/ground at the blower motor when it is failing to come on will tell you if the problem is there or further up the signal path.

[Richard Oben]

Taking it in tomorrow, we will see what the Experts come up with, Thanks, Richard.