Thats good going, why dont you lube it a bit and see if it helps, does this issue mean the tailgate hatch lights always stayed on causing you drain?

if your hvac blower is still running...or turning on by itself when the ignition is off...this is a classic FSR/FSU issue that has been discussed ad nausium over the last decade across all the e46/e39/e53 forums.

The blower stopped after like 1/2 an hour. I will be monitoring it for the next couple of weeks and thinking of just replacing the fsu as a precaution.

Qsilver7 we are not talking about the small fan behind the air con controls are we?

What we are saying here is that the fan emits a faint whirring noise(only heard when we put our ear to the ac control panel)!
Are you saying that fan should be completely silent when ignition is turned off and not go off 16 mins later when car goes to sleep mode?Also,the fan shouldnt come back on as soon as car "car wakes up",like opening a door?
Mine goes comes on /off with car sleep mode.Also ,I do not have any amp draw when car is in sleep mode,except from monitor (inconsiderable 0.03 Milliamps )
If I had a bad FSR ,I would get a considerable amp draw even when car is in sleep mode!!

30 mins is too much ,almost twice as long as sleep mode´s 16 mins.That maybe your problem!
How loud is the fan ?Do you need to put your ear close to the air con control panel or can you hear it well from the drivers seat?

That is crazy car started this morning wife drove it to the gym 2 hours later battery dead at 7.5 v.
Talking it to my mechanic.

Omodos...I'm not sure everyone is on the same page. My comments above were about the HVAC blower since salnj mentioned he thought "the heater" was still on....which I interpreted as the blower that sends air thru all the air ducts...and is controlled/regulated by the FSR...which when it (the FSR) fails...can turn itself on and off or act erratically....whiich can drain the battery if it turns itself on while the vehicle is parked.

And it sounds like some are referring to the little sampling fan inside the IHKA control unit that comes on when the car AWAKES and turns off when the car goes to SLEEP. The sampling fan has a very small electrical draw and onlydraws cabin air into the IHKA so that it can regulate the set TEMP on the IHKA.

To clear it all out seems I have 2 issues.
1. The final stage unit. That is what my mechanic diagnosed and said to come back tomorrow and he will replace.
On my way home after I left the mechanic turned off the heater through the hvack control but the heater turn back on for several minuts before it shut itself down.

2- trunk upper hatch lock is sticking you need to push the button couple of times before it opens. Put lubricant on it lets see if that will help.

salnj and qsliver7 sorry I muddied the waters....salnj last post clarified all the queries I had...bad fsr means his heater blower(s) coming on willy nilly, and his trunk latch has a problem, both which maybe draining his battery