[PINeely]

Hey guys, a friend of mine has just picked up a 2006 325i. Car is in great shape except for having had the whole water in the footwell problem. As a result the car was sold to him without A/C and with the suggestion that the final stage resistor needed to be replaced. We ordered one along with a new blower motor since we figured that the old one would be fried from the water (it was).

Today we installed both parts however the air still isn't blowing. Checked the fuses and they all seem fine. I tried it with the motor laying in the footwell and it wouldn't spin at all. Next we tried the old FSR with the new motor and still no results. Both before and after we could hear a faint squeaking noise from the vents when the defogger was turned on.

Is it possible that one of the replacement parts is defective? Is there a third component somewhere which could be bad? I thought about switching the parts into one of mine to see if they work.

Thanks!

[PINeely]

Just plugged both parts into my car and both worked fine. What do I need to look for now?

[DSB335d]

Could be a number of things. Low pressure or high pressure switch. You can check them with a dmm (multi meter) I believe there should be 12v present on either side of the switch. Could be an issue with the a/c condenser fan not turning on. You can check voltage coming into the fan and leaving it. Check the a/c relay, it should click when you turn the a/c on. What about the a/c controller in the dash; is it electronic or manual? Good luck.

[PINeely]

I don't remember hearing the relay click when the blower was turned on. Will check this as it could have been damaged by the water.

[J02 335i]

So technically your have a problem with the blower motor, not the A/C? Right?

[PINeely]

Originally Posted by J02 335i

So technically your have a problem with the blower motor, not the A/C? Right?

Thats correct.

[DSB335d]

Have you replaced the resistors for the blower motor? It should work on high speed regardless as high speed has no resistance.

[PINeely]

The final stage resistor has been replaced but no air even on high. Don't know if there is another resistor or not. There's a few other electric components in the parts diagram though. Pull them all and look for corrosion?

[Surly73]

Originally Posted by PINeely

Just plugged both parts into my car and both worked fine. What do I need to look for now?

You've checked fuses, right?

[mike3000fl]

After all is said and done he is going to have to fix the windshield cowling that allowed the leak to happen in the first place.

[PINeely]

Originally Posted by Surly73

You've checked fuses, right?

We have

Originally Posted by mike3000fl

After all is said and done he is going to have to fix the windshield cowling that allowed the leak to happen in the first place.

We took care of that already since the new parts would just get ruined when it rained next.

[PINeely]

UPDATE:

We took another crack at getting it fixed today. This time we took out the glovebox and again tried withe the car disassembled and the motor laying in the footwell. Still no luck but when the air is turned on we can hear something that sounds like air hissing slightly. The sound shuts on and off with the air (on the dash; motor still isn't spinning). The hissing is definitely coming from behind the dash and is most audible from inside the fixture for the blower motor.

Any ideas?

[deadmn1337]

When you turn the A/C on does the compressor come on? If the compressor comes on, is the hiss only when its on? If so, then there might be a leak in a/c lines. Have you tested all the wires leading to the blower motor? if the old motor went bad water could have corroded the wires going to it so you are getting power through the wires.

[PINeely]

Compressor comes on and the noise starts but we didn't run it long enough yet to see if they are connected

I've read a little about wire corrosion problems in these cars, particularly the blower motor wires seems to be affected. I'll check these as well.

[Surly73]

Originally Posted by deadmn1337

When you turn the A/C on does the compressor come on? If the compressor comes on, is the hiss only when its on? If so, then there might be a leak in a/c lines. Have you tested all the wires leading to the blower motor? if the old motor went bad water could have corroded the wires going to it so you are getting power through the wires.

Errrrr. Wouldn't the "hissing" be the refrigerant flowing through the AC system and spraying from the evaporator valve into the evaporator coil? This would be normal.

If the replacement parts all work in another car (this is what he's said) and the fuses are all OK, you might have problems with the IHKA module itself or who knows what else. It might be time to find someone who can read full codes out of the IHKA and see what it thinks. Note: this might be a dealer, or it may be someone in the area who does coding. It's worth checking if there's voltage present in any of the wiring harnesses which operate the fan but you might be getting in over your head compared to possibly giving someone $50-$100 and possibly having the answer then and there if the IHKA itself knows what the problem is.

A bad FSR/blower could have taken the IHKA output stages out with it, for instance.