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Discussion Starter #1
I'm having a battery drain issue where if I let my car sit over night the battery drains. I changed the fsr hoping that would solve the problem but no luck. Any thoughts on what else it could be. Is it the Hvac itself that needs replaced? Any other ideas would help. Thanks
 

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I'm having a battery drain issue where if I let my car sit over night the battery drains. I changed the fsr hoping that would solve the problem but no luck. Any thoughts on what else it could be. Is it the Hvac itself that needs replaced? Any other ideas would help. Thanks
You need to do a parasitic draw test to locate the fuse to the source of the drain....watch this video first...
https://www.youtube.com/watch?v=KF1gijj03_0
 

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I've done the parasitic draw test and I've tracked it to fuse 63 witch just says air conditioning on the guide now I've replaced fsr, climate control unit, and the a/c relay. Still have a drain but if I unplug the fuse no drain. I really don't know what else to replace other than the clutch fan that this fuse is suppose to power
 

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I've done the parasitic draw test and I've tracked it to fuse 63 witch just says air conditioning on the guide now I've replaced fsr, climate control unit, and the a/c relay. Still have a drain but if I unplug the fuse no drain. I really don't know what else to replace other than the clutch fan that this fuse is suppose to power
Rich24......behind the glove box is a "relay panel" You may have a bad relay. Relay #1 & #4 are for the A/C. Starting at the 9 O'clock location & move in a clock wise direction, #1 is at the bottom 9 O'clock & then count four around for #4. Bentley manual has a picture on page 610-11. Pull each separately & see if the 'draw' stops on your millimeter. If it does, replace that relay. Not sure what else to check.
 

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^ Good point and if the relay is stuck, there would be constant battery voltage in the wire to the A/C clutch with the ignition off.
 

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Discussion Starter #6
Okay thanks guys I'll check it and see, I didn't know #1 was for ac as well I replaced #4 without testing it because I thought only #4 was a/c and it did stop it
 

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// Quandt AG (Retired) //
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NP - I've been having this same issue on my 330i and diagnosing the cause is one of the most frustrating things I have experienced as an e46 owner. Biggest problem is it's intermittent. Sometimes the car can sit for a few weeks and turn over NP. Other times after 1 or 2 days the battery is dead.

If the relay is getting stuck periodically that might explain why the intermittent symptom.

Report back when you get a chance thanks.
 

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Discussion Starter #11
Okay I've already changed relay #4 which is all the ac is on mine and I still have a drain so idk at this point
 

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Okay I've already changed relay #4 which is all the ac is on mine and I still have a drain so idk at this point
Interesting...a picture of what you have might help.

Here's what the Bentley manual shows:


Relays 3,4,5,&6 are across the top in the 1st picture; they got cut off on the PDF manual I have. Does your panel look anything like this?
 

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This is what I've got
Rich24...Hummmm....that's interesting. You right. The pinkish one must be the #2 relay. I looked thru the Bentley & could not find anything else on the A/C relays. Maybe the earlier model is different. Sorry.....
 

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Discussion Starter #17
It's okay thank you for your input either way. I think the next step for me will be the clutch fan
 

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Rich24 - are you meaning the AC magnetic clutch compressor? I have this same issue right now so I'm following this thread closely. What's feeding the ac compressor current when the car is turned off if the relay is working correctly? I should be able to measure a draw at the trigger wire across ground if this is the cause of the drain?

 

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I'm going to try to single out just the clutch fan. Maybe it has a draw on it. I'm going to on hook it and see if it kills the draw
 

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I'm going to try to single out just the clutch fan. Maybe it has a draw on it. I'm going to on hook it and see if it kills the draw
Rich24 - You mean the AC compressor magnetic clutch - depicted above? I'm confused you don't mean the AT clutch fan that is attached to the WP? It is not electrical and wouldn't draw anything.
 
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